Getting the right balance between form and function is a real dilemma for vendors of connected handhelds, and nowhere is that more apparent than in devices that include a keyboard.
Probably the most usable example we've seen is HTC's TyTN, whose slide-out keyboard is large, making it easy to use at speed. HTC has reprised the sliding keyboard idea in its P4350, which is available network-free from sellers such as Expansys.
The HTC P4350's design won't set your heart racing. Its mostly black livery is offset by a bank of silver buttons sitting beneath the screen. These comprise Call and End keys, a button that calls up the Windows Mobile Start menu, an OK button, two softmenu buttons and a navigation key with a central select button. All of these buttons are large and shouldn't trouble even the stubbiest of finger.
At 59mm by 109mm by 17mm, it's slightly shorter than the TyTN, one millimetre wider and a fraction thinner. Overall it does offer a sliding keyboard in a slightly smaller package than the TyTN.
The bulk of the front of the HTC P4350 is occupied by a 240x320-pixel screen measuring 71mm from corner to corner. When you slide the two halves of the device apart to reveal the keyboard, the screen automatically reorients from portrait to landscape mode, giving the P4350 the appearance of a miniature laptop.
The keyboard is not large -- just 90mm wide and 26mm tall. The individual keys measure 9mm by 6mm and there's a double-width space key.
A pair of softmenu keys sits above the Qwerty row, while the number keys are embedded and very clearly marked out in blue against the black background. The numbers, and a range of symbols that also double up on most of the keys, are accessed via a key combination. The keys have little travel, but there's enough movement for confident typing.
HTC has found room for two tiny lights, one to indicate when the Fn key is active, the other showing that Caps Lock is on. Overall, HTC has made the keyboard as usable as possible, and therefore extremely effective. It is, of course, too small for touch-typing, but for mobile email and some document editing on the fly it's certainly better than many other keyboards on handheld devices.