While the general trend for mobile devices is to go smaller, ever smaller, T-Mobile's Ameo causes a raised eyebrow for being somewhat larger than is the norm. It is also an eye-catcher because it comes in two pieces, with a main section and a separate keyboard. And the two pieces connect in a quite ingenious way.

The Ameo is a Windows Mobile Pocket PC, with plenty of features crammed in including GPS, 3G support and Wi-Fi. Its huge screen measures five inches from corner to corner, and while you can hold it to your ear to make voice calls it is rather large for this. Its real forté is video calls, as it can show both you and the caller in large on-screen windows.

The Windows Mobile software is supplemented by a couple of extras including the superb Opera Web browser. One of its highlights is the ability to open Web pages in tabs, much as you would do with a modern desktop browser. There's a button to the bottom right of the screen which you can use to control scrolling within the Web browser simply by tilting the Ameo. Sounds strange, that, but it works well enough.

We said the separate keyboard affixes to the main unit in an ingenious way. You hold the two sections close and magnets cause them to snap together. They don't make the strongest connection we've ever seen and it is easy to dislodge the two sections by accident, but if you are able to leave the Ameo in a safe corner on your desk the connection works perfectly well.

The keyboard is too small for touch-typing on, and in fact not a great deal faster to use than some of the better QWERTY keyboards on small Smartphones. You can't hold the Ameo in two hands and use the keyboard with your thumbs, because it is top-heavy and there is always the danger of the two sections falling apart from each other.

We haven't finished with the surprises yet. The Ameo has an 8GB hard drive whirring around inside it, giving it a huge amount of storage compared to other Windows Mobile devices. It has an SD card slot too.

The Ameo comes with two carrying cases, one of which is designed to accommodate both sections either separately or fixed together. It is certainly a clever piece of kit, but weighing 355g and being rather bulky it may prove somewhat unwieldy to carry around. And as already noted, it is not ideal for making voice calls.

We like the Ameo because it takes a different approach to Windows Mobile. But we aren't sure it is a serious replacement for a mobile phone, and as a connected PDA it is clever but also rather large for the pocket or bag.