One day, all mobile phones will have something similar to the Sapphire Mini Projector 101 built in.

In fact we won't even be calling them mobile phones by then, so omnipresent they'll surely become. Who knows, maybe they'll simply be embedded in our foreheads, and we'll receive a 6G signal directly to our frontal lobes.

For now, though, we have to make do with the Mini Projector 101, a projector that's the size of a mobile phone. I for one can just about put up with that.

Okay, I realise that it only outputs at the ol' school VGA mode of 640x480, but hell, that's good enough for a little bit of projected action on the move.

Now I'm not going to lug a full projector around with me on holiday, as much of a techno-obsessive as I am, but being able to slip one of these into your suitcase means you can forget about rubbish foreign telly on your travels.

Limited battery

The battery is a little limited, too. And you'll have to fill your boots with sub-two hour movies if you want to watch them unplugged from the mains.

In a decently darkened room, though, you'll get a fairly good image. And the upscaling to your laptop res is fine for the odd non-HD video.

The stumbling block is the price. If it were a professional PowerPoint projector to lug around meeting after meeting, you could justify the £200+ price tag.

Unfortunately, it just isn't clear enough without blackout curtains. As such, it's a lot of cash to spend on something that's just going to be slung in the overnight bag or holiday suitcase.

The Vivitek D511 is the first data projector we've seen from the Taiwanese company and on first impressions it's a great example of what an entry-level projector should be. The compact body of the projector weighs in at a portable 1.9kg and while it's not the toughest construction around, it offers good value for money.

The manual focus ring protrudes from the front of the casing, while the zoom is fitted behind it and hidden away inside the body of the casing.

Buttons on the top of the unit offer the standard array of controls, with a large Power button and a ring below this with Menu, Source, Auto and keystone correction controls.

The Vivitek D511 ships with a mini remote control that mirrors the controls on the top of the unit. The menu controls are easy to get to grips with, but you will find that some of the controls are hidden away, such as the Eco-mode.

You'll find a full array of ports on the back consisting of the standard D-sub, s-video and component ports, and an HDMI port for connecting to a digital source.

With full support for 720p output, the D511 has a native resolution of 1024 x 768 pixels, but will upscale to 1600 x 1200 pixels with ease. This projector is also 3D ready and so is capable of making the most of the big changes in presentation technology.

When it came to image quality, we found the D511 had quite a short throw range, so it isn't ideal for larger meeting rooms. In the home or small office, however, images look crisp and sharp.

Dropping the projector down into Eco-mode marks a noticeable drop in the noise generated by the fan, while it still manages to maintain a respectable brightness level.

The Vivitek D511 offers a fair degree of future-proofing for such an affordable data projector. Sure, it lacks the build quality of some other machines, but it still represents great value for money.

The Viewsonic PJD6211 is the most cost-effective data projector here. It takes the standard design route for a DLP device, being a squat device that sits length-wise with the lens fixed at one end and a large vent along the front.

It's quite compact but with a weight of 2.6kg, is not ideal for taking on the road. You will find it is a decent machine for sharing between rooms in an office, or possibly a school.

The lens has the usual manual focus and zoom rings and we found getting this projector up and running to be quick and easy. Controls on the top of the unit proved easy to get to grips with and while the menu system is comprehensive, you do need to scroll through quite a number of pages to get it set up to your liking.

With a brightness rating of 2500 ANSI lumens you'll be able to use this projector in most lighting conditions with ease. What's more, it has quite a small throw range, making it ideal for use in smaller meeting rooms and school classrooms.

Sadly, we found image quality to be fairly unimpressive, with the whites in our presentation test having a yellow tinge to them. Video seemed more appealing, however, with little in the way of pixelation, even during a fast action scene.

Running in Eco-mode dropped image brightness down by a noticeable degree but the cooling fan continued to run noisily.

Connectivity on the rear shows the entry-level roots of this device, as you won't find any digital ports. There are comprehensive analog connections for use with multiple analog sources, however, highlighting the office-based functionality of this device.

Odd then that the PJD6211 comes with 3D ready support. This is due to the 120Hz refresh rate of the lens and its native resolution of 1024 x 768 pixels.

The Viewsonic PJD6211 data projector offers decent value for money but unless you're on a tight budget we feel that it does have rather limited appeal.

The Optoma EW330 is the most expensive data projector in this group test, but it's also the smallest and lightest. With an overall weight of just 1.2kg, it is perfectly designed for life on the move. The compact chassis feels solid and is more than tough enough to be carried in a bag alongside your laptop.

The zoom ring is hidden away inside the main body of the projector, while the focus ring sits on the outside. Through the use of a clever design it works exceedingly well without protruding too much. The menu buttons are a little small and fiddly to use at first, but the menu software is easy to get to grips with.

With a brightness of 2200 ANSI lumens and a standard 2000:1 contrast ratio, you can use this projector in most lighting conditions. We found image size to be acceptable for smaller meeting rooms, but not nearly big enough for larger spaces.

Connectivity is kept to a minimum, with a single D-sub port and s-video connection. However, there is also an HDMI port in place, so you can connect to a high-definition (HD) digital source with ease.

What we like best about the EW330 is the image quality it delivers. During our presentation tests we found it offered a very sharp contrast between black and whites, with documents looking crisp. With its 16:10 aspect ratio, it's designed for use with older laptop screens, so you'll find the native resolution of 1280 x 800 pixels leaves a slight letterbox effect in place when running widescreen movies.

In many respects, the only real flaw with the EW330 is how hot it gets. We also found it quite loud, as the fan needs to work hard to keep the heat under control. If you're using it for presentations on the road, you'll need to wait for it to cool down properly before packing it away.

Overall, the EW330 is a great projector. We like the compact size and connectivity is decent, but most of all the image quality on offer is simply outstanding.

LCD projectors like the Epson EB-W7 tend to be slightly larger than DLP machines, but in its favour the EB-W7 has a great look. The white plastic finish feels solid and the menu buttons, while well spaced, are a good size.

The projector itself has an overall weight of 2.3kg, which gives it a semi-portable feel, but it is a rather bulky machine to carry around. The lens is hidden away under a protective cover, so you run less risk of damaging it in transit or simply when stowing it away. It's a manual cover and underneath you'll find good-sized focus and zoom controls, so ensuring images are pin-sharp is an easy task.

Connections on the back of the system are adequate. There is no HDMI port, but you'll find the full array of analog ports for connecting to your laptop. We found that setting up the projector was quick, but using the onscreen menu proved a little complicated, so fine-tuning settings could be tricky.

The 2200 ANSI lumens brightness rating makes this a bright projector and we found it more than usable in a range of home and office situations.

Our presentation test highlighted how usable this device is. With crisp whites and sharp blacks, backed by a good throw-range, this is ideal for an office environment. Our video tests also proved more than acceptable, with a great range of colours that had real warmth to them.

However, with its native resolution of 1280 x 800 pixels, this is a 16:10 aspect ratio projector, so while movies look sharp, it doesn't natively support widescreen images, so there is a letterbox effect.

The Epson EB-W7 is a good all-round projector that delivers sharp and warm colours. The lack of a high-definition HDMI port limits its future-proofing, but for offices and schools where older laptops hold sway, we feel this is a cost-effective and highly usable machine.

The Acer S5200 data projector stands out for two reasons. First is its size. At 3.5kg, it's no small fry, so is not intended for use anywhere other than an office or home environment. However, its hulking size does mean you'll find a comprehensive array of ports on the back, including network options. It's a handsome device, but you'll need to handle the lens with care, as it protrudes from the front of the case.

The second reason the S5200 stands out is that, with a brightness rating of 3000 ANSI lumens, it's powerful. Even when it is dropped down into Eco-mode – which offers a slightly less bright image – the projector still delivers great image quality.

There are nine control buttons on the top of the S5200, offering the standard functionality. This is mirrored by the supplied remote control, which is large and easy to use.

Sadly, while the menu controls are comprehensive, they are spread out across a number of pages, so navigating the menus to get the best out of the projector does take a little time. Thankfully, the addition of a dedicated Acer Empowering button allows you to quickly change usage modes, making it somewhat easier to get started.

With a maximum resolution of 1600 x 1200 pixels and the addition of an HDMI port, you'll be able to view HD content with ease. Like the Vivitek in this group this projector is also 3D ready, so can be used with any laptop with a 3D accelerated graphics card.

We also like the fact that you can easily change from a 4:3 aspect ratio to a widescreen 16:9, so switching from presentation to movie mode is quick and easy, for example.

The Acer S5200 delivers a great deal at a good price. While it lacks mobility and seems a little too component-rich for home use, it would make a great choice for a busy school or office.

Viewsonic has a wide range of data projectors and the PJ358 is fairly typical of the range. It uses LCD technology and is a boxy and rather plain looking projector.

It shares the same design as the Hitachi CPX4 and, while rather understated with an overall weight of 1.8kg, it's a portable device and easy to slip into the supplied carry case.

The focus and zoom rings are neatly tucked away in the main body of the device, but you won't find a protective lens cover, which may cause problems later on.

Simple setup

The menu buttons on the top of the unit consist of three options – On, Input and Menu – and they work well, making setting up the unit extremely easy. Three indicator lights give you the projector's status and are also very easy to decipher.

With its 2000 ANSI lumen brightness, you can use this projector in most rooms without having to exclude too much exterior light. We found image quality to be more than acceptable and, if you can exclude light, we'd suggest opting for the lower 1400 lumens Eco mode, which not only allows a longer life for the bulb, but also reduces the noise and heat produced.

The design has been in production for close to two years. It is starting to show its age, which is reflected in its entry-level price. The 4:3 aspect ratio is ideal for business presentations, but less impressive when trying to watch a movie, as you'll need to upscale the lens to make it fit.

When it comes to connections on the rear of the unit, they use the standard analogue connections of VGA and S-video. However, you will find two VGA-in ports, so you can switch between two presenters without having to change laptops. If you've no interest in adding a laptop, you can use the USB port for connecting a USB memory stick that will automatically read JPG images for basic slideshow presentations.

The Viewsonic PJ358 is a good all-round machine for the price and while there are signs that it's starting to show its age – its 4:3 aspect ratio for example – it proved a reliable and likeable machine.

The Optoma EP728 stands out from the competition because of its small size and weight.

When packed in its carry case it is half the size of most rival projectors, which will be welcome news to anyone who has to take a projector on the road.

Despite the small size, this is a regular DLP projector with an XGA resolution that can be resized to a widescreen image of 1400 x 1050 pixels.

Full connectivity

The ports and connectors are lined up across the back of the projector and we were pleased to see Optoma has managed to squeeze in a full selection, despite the size.

They consist of VGA output, VGA input, DVI input, S-Video output, audio jack and USB port. Optoma adds to your options by including an adapter that converts S-Video to Composite.

Awkward operation

This projector uses a focus ring around the lens that is trickier to reach than the controls on the other projectors, which have a simple lever next to the zoom control.

Then there's the remote control, which is a reasonable example of the species. However, the layout is confusing as it is covered in pairs of plus/minus buttons.

While we're complaining, the set-up menus would also benefit from a bit of work to make the options crystal clear. Once you get to grips with the Optoma, it's easy enough to figure out, but if you are an occasional user you might find it exasperating.

Deep black levels

Using the EP728 in Bright mode gives you a decent picture that is sharp and clear, while the 33dB noise rating is less intrusive than you might expect.

The picture isn't perfect as it has a relatively harsh image that we used to associate with DLP technology. However, blacks do look good.

Switching to Standard mode makes the projector noticeably more quiet, but it makes the picture too dark for our tastes. As you can see, the Optoma isn't perfect, but it is a very good compromise and the small size makes it a favourite of ours.

ViewSonic has built its PJ551D around a 0.55-inch DLP chip that offers a native resolution of 1024 x 768 pixels.

It lets the side down slightly as the maximum resolution can only be stretched to 1280 x 1024 pixels, rather than the widescreen 1400 x 1050 pixels that is offered by more versatile rival projectors.

Modest connections

The back of the ViewSonic has the smallest selection of connectors we have seen in a long time with a VGA input in the middle and S-Video and Composite connectors to one side.

There's a USB port marked 'Service' and that's your lot. The PJ551D doesn't have a speaker, so there is no audio connection.

The noise rating of the PJ551D is around the 30dB mark and is also rather noisy, but when you switch to Eco mode the edge is taken off whites and blacks, yet the noise level barely drops.

Eco mode

If you constantly run the projector in Eco mode, the lamp life only increases from 3500 hours in Normal mode to 4000 hours in Eco, which is such a small difference that it is unlikely to influence anyone. This pain-without-gain means that we recommend you stick to the noisy Normal mode.

The credit card remote is so small that at first we couldn't find it in the box, which sounds silly but we were looking for a regular TV or Hi-Fi remote.

Once we'd found it we had a grim time as the remote is very fiddly and the rubber buttons are imprecise. You can get round this by using the control buttons on top of the projector, but there's no avoiding the fact that the set-up menus are poorly arranged.

Underwhelming package

This is a cut-down, no-frills DLP projector with a low price. However, we found more highly-specced rivals discounted to the same price, so the PJ551D doesn't have a killer advantage on that score.

It's a competent projector that does a reasonable job, but it lacks any interesting features and failed to make a lasting impression.

InFocus takes the prize for 'heaviest contender' in this group, as its IN2104 tips the scales at 3.1kg. Its slabby looks add to the impression of a bulky projector, despite it having the same dimensions as the Acer, Epson and Viewsonic models.

To make matters worse, the power cord sticks out of the left-hand side of the unit, which adds to the footprint of the IN2104, as the rest of the cables attach at the rear.

Extensive connectivity

There's plenty of space on the back and InFocus has taken the opportunity to add plenty of ports and connectors.

There are S-Video and Composite outputs (but no cables), three mini jacks for audio input and output, dual VGA inputs, a VGA output, USB and a Serial port.

You also get a 5V power point for a LiteShow II Wireless adapter so you can control the projector from your laptop without hooking up a cable, but you'll pay £100 for the privilege.

Noise problems

When you set up the IN2104, you'll find the zoom range is so poor you'll very likely move either the projector or the screen to change the size of the projected image.

The 35dB noise rating is unpleasantly loud and the cooling system makes a whining noise that adds to the noise pollution. Changing from Normal to Eco mode drops the noise level by 3dB, which makes very little difference, although it increases the bulb life from 2000 to 3000 hours.

Making the Eco change introduces you to the remote control and the set-up menu, which is awkward to use as it only shows six items on each screen. This wouldn't necessarily be a problem, but one of the sub-menus has 24 items, so it can be quite laborious to make adjustments.

Reduced price

It came as a pleasant surprise to find the picture is bright, sharp, clear and pleasant on the eye, but getting to this point is too little too late.

We've given the price as £433, but at the time of writing LambdaTek is selling the InFocus for £369, which makes the IN2104 slightly more tempting but it's not enough to overcome the downsides of this model.