There was a time when projectors designed for corporate environments were all huge – and virtually immovable. And while permanent installation projectors continue to be built (we've included a few in this list), there's a definite trend towards the tiny.

Projector makers are creating ever-smaller, brighter and more versatile beamers. It's recognition that more presentations are given not in boardrooms, but by road warriors and mobile workers in unpredictable environments.

Projectors are getting smarter, too. They now include everything from Wi-Fi connectivity and iPad mirroring to digital file playback, built-in storage and media playback software that plays nicely with presentation-friendly file types. Support for Microsoft Office formats, like PowerPoint, plus PDFs and JPEG photos is now near-universal. Who even needs a laptop?

As lamp life, as well as portability, becomes important, the industry has moved en masse to LED engines, which find their killer app in Pico projectors. However, these tiny models remain something of a gamble. Small and easy to carry they might be, but what they give in terms of portability these pocket-sized projectors often take in brightness and resolution. After all, where's the benefit of a small projector if the presentation it produces makes you look unprepared?

Choose your projector wisely and remember that resolution is less important then brightness (measured in Lumens) if you're likely to want to project in brightly-lit rooms during the day.

1. Philips PicoPix PPX2055

£120/AUS$205/US$19

Philips PicoPix PPX2055

It weighs just 114g, measures a mere 72 x 72 x 27 mm, and easily fits into a jacket pocket for instant on-the-go presentations – and it's completely powered by a USB cable attached to a laptop.

Its resolution is just 854x480 pixels – not even HD quality – and it's bright enough only for 50-inch images, but this is the most wallet- and travel-friendly design out there. Setting-up the PicoPix PPX2055 is no more complicated than choosing a shortcut on the desktop of a laptop, and hitting OK on the first and only set-up screen.

Picture quality isn't akin to a home cinema of any kind – it's neither bright nor nuanced enough. But it's certainly good enough for basic presentations. The only drawback is that it doesn't work with Apple laptops.

Verdict: A mini pocket projector that's bright enough for 50-inch presentations.

Read the Philips PicoPix PPX2055 review

2. Acer Pico C120

£210/AUS$268/US$230

Acer Pico C120

It's not the best nor the brightest, but when it comes to portable projectors on a budget, Acer has got it nailed. Achieving around 100 Lumens of brightness, this tiny micro projector – one that gets all of its power from the USB port of a connected laptop – is the darling of the portable Powerpoint presentation.

Bigger and brighter than the aforementioned Philips, it weighs 304g and measures 120 x 82 x 26mm, but manages only 854 x 480 pixels. Pride of place in Acer's Travel Series, the C120 will appeal to any road warrior who needs to impress with an instant Powerpoint presentation – though a reasonably dingy environment is a must. If only it worked with Apple products, too.

Verdict: Less is more on this astonishingly small DLP LED Pico PJ.

3. Epson EB-X11

£409/AUS$526/US$654

Epson EB-X11

Epson's EB-X11 is an attempt to please everyone in a reasonably compact, highly capable package. Measuring just 295 x 228 x 77mm and weighing 2.3kg, the EB-X11 is made for a life on the move (check-out the handy lens cover that instantly shuts-off the lamp and speakers), though it doesn't come with Wi-Fi.

Its high brightness rating of 2600 Lumens is useful, as is its HD-ready 1024 x 768 resolution; this is a big cut above the Pico PJs. Highly portable and very dependable, the EB-X11 is so easy to set-up and fulfils its simple brief with the minimum of fuss. It's a lesson in how to make a great classroom projector – but don't expect any extras.