You certainly get plenty for your money in one of these devices. Combining all the power and features of a Pocket PC-style PDA using the Windows Mobile operating system, along with the versatility that comes with mobile phone connectivity, you get the best of both worlds - voice calls, email, and web browsing plus the stack of productivity tools, entertainment applications and flexibility that a smartphone can deliver.
The trouble is, packing all these features into a single device can mean that the hardware is rather large to carry around.
But that is changing. We've seen a number of Pocket PCs becoming somewhat smaller in size recently - to the point where they are little larger and heavier than a standard phone-style Windows Mobile Smartphone.
The ETEN M600 is a perfect example of what we mean. It is brimming with features. It is small enough to carry in most pockets.
And it is connected - your SIM lives underneath the battery. ETEN boosts the state-of-the-art Windows Mobile 5.0 software with a large range of its own, and apart from one or two annoyances has done an all-round good job.
The M600 can be bought online from Expansys (www.expansys.com) either on a contract - at a range of prices depending which deal you opt for - or SIM-free, without a contract. At the time we went to press, the handset-only price was around £380, though contract prices ranged from free (on heavy-usage deals) to around £285 (for light consumer tariffs).
This is a quad-band handset, so you should be able to use it on your international travels with no problems at all. Because of its small size, you can hold it to your ear to make voice calls without feeling like a bit of an idiot.
If you'd rather use a Bluetooth headset you can. You could even have a go at using Skype for voice over IP calls, because 802.11b Wi-Fi is built in too. Strangely, though, infrared is missing.
As is usual with Windows Mobile 5.0, the built-in memory is Flash based. There was 84MB free on our review device out of 128MB installed. That is quite separate from the 33MB set aside for actually running programmes. You can add memory with an SD card, and the slot is in the top of the casing for easy access.
The touch sensitive screen is quite small - it measures just 2.8 diagonal inches. But it packs in 320x240 pixels, and is exceptionally bright and sharp - though it does suffer a bit in direct sunlight. The stylus is lovely; it extends to a full 12cm long when you extract it from its hidey hole, which means it feels like a pen in the hand.
But its housing becomes exposed when you take the battery cover off, and we found it had a tendency to fall out without the battery cover holding it in place. Obviously you won't expose the battery very often, but it is a point worth noting for when you do.
It is unusual these days for a Pocket PC to be bundled with the desktop cradle, but in this case you do get one and it has a slot for charging a spare battery if you want to invest in one of those. You also get a rather nice carrying case with a belt clip and a wrist lanyard, and a pair of stereo headphones.
The extras don't stop there. ETEN has gone to town with its provision of extra software. On the Today screen, for example, there is a battery monitor giving a graphic display of how much energy the device has left.
Two shortcuts are huddled at the bottom right corner of the screen. One takes you to an application called Scenarios, which lets you choose between several phone profiles, the other to an application which lets you manage the GSM, Bluetooth and Wi-Fi settings.
There is also a further row of large icon-based shortcuts. One of these takes you to the running programs list so you can quickly shut these down and free-up memory, others take you to call log information. Tap another icon and you can choose to display shortcuts for all the applications on the device.
If you don't like the Today screen at all, then ETEN's M-DESK is an icon driven alternative. And there is more. For example the Voice Commander software lets you speed dial by voice, but also can be used to play music, get to your SMS messages, start software running, and more.
A button on the left edge of the casing starts it up. Bring Voice Commander together with the other things we've mentioned and this must be one of the most user configurable Pocket PCs available in terms of customising quick access to software and services.
Meanwhile, if you want to get busy with the 1.3-megapixel camera you can use ImageMaker, ImageWizard and Multimedia Manager to edit and view photos. The camera itself is launched by a button on the left edge of the casing.
We're used to using options screens to get to the various settings that built-in cameras offer, but in this case things are much simpler.
Start the camera and the whole screen turns into a viewfinder. Tap a tool icon and a frame around the viewfinder becomes filled with large icons which let you very quickly control everything you need.
There is one for turning the flash on and off, one for flipping between landscape and portrait mode shooting, one for choosing image resolution (1280x1024, 640x480, 320x240 or 176x144), one for selecting white balance settings, one to send the images to the device or an SD card...the list goes on.
The Eten M600 is, we've already noted, one of the most efficient to use Pocket PCs we have seen. Yet it is not overly complex to get to grips with. Setting up voice tags and configuring the Today screen with icons was easy - though newcomers to Pocket PC might be annoyed that the user manual is supplied on CD ROM.
We had no problems with calls, with quality high, and we felt fine holding the M600 to our ear. There is a good range of catchy ringtones to choose from.
Battery life was quite good, too. We got through a few days use at a time between charges, and when we did a run-down test asking the M600 to play our favourite MP3s with the screen on, it managed seven and a half hours on a single battery charge - pretty strong going.
The M600 is a very attractive, compact device. With plenty of customisation and a lot of features over and above the standard Windows Mobile 5.0 offerings, there is still enough memory left for you to add plenty of your own software. Lester Scott
CAMERA: The camera lens is on the back of the casing, along with a tiny flash unit and self portrait mirror
CONTROLS: A bank of buttons give you access to the camera, volume, and Voice Commander software
TOUCHSCREEN: Tap the screen to control functions or use the softkeys to navigate
MEMORY CARD SLOT: You can add to the built-in memory with swappable SD cards