I've been using an interesting combo of input devices lately. Namely, Art Lebedev Studio's Optimus mini three keyboard (left) and I-ROCKS' KR-6600 'nano slim' keyboard. The two keyboards are relatively unique in that the mini three is the first keyboard to implement OLED displays for the keys, and that the KR-6600 is probably the smallest 'full set' keyboard you'll find on the market. It's barely bigger than the Half Keyboard I used for my wearable computer back in the old days.
Optimus mini three
Optimus series of keyboards have made, and is still making a lot of buzz because they employ active screens to represent the functions of each keys instead of having static silk-screened prints like most keyboards out there. However, only one kind of the series, the mini three, has been put to actual production as of this writing. A full-sized keyboard, the Optimus-103, is supposed to be sampling in Spring 2007 with full colour keys, after a black-and-white passive LED version was to come out for pre-order on December 12, 2006, then scrapped altogether.
I've only been able to start using my mini three (it's been about two weeks) because the Mac driver, currently in early alpha stage (using 0.34a version right now), hasn't been out for very long. It's starting to be barely usable. It doesn't seem to recognize the focused application's profile profiles yet, so I'm using it mainly to display time/weather and launch/switch applications. There's an audible high-pitch noise (fixed in the 2.0 hardware, apparently) but other than that it's alright. I can see some good potentials for this keyboard once the configuration application stabilizes and gets more functions like accepting keyboard macros.
KR-6600 - as big as my hand
As for the KR-6600, it's so small I can almost cover the whole thing with one hand. As with the foldable keyboards out there, which are slightly bigger than this one when fully opened, the KR-6600 is highly portable: very light, thin, and small. I-ROCKS claims it was made with small portable PCs (e.g. UMPC, Tablet PC) and industrial applications in mind. The full alphanumeric keys are there, with some 'less used' keys being pushed aside into 'second mode' keys requiring the press of Fn button to activate. Total key count is 77.
While I commend I-ROCKS' effort to cram so many keys into such small dimensions, I have encountered noticeable flaws in its execution. It claims that the keyboard's pentagraph key structure ensures accurate typing, but I found it to be far from the truth. I've used small keyboards for more than 5 years, so I'm rather comfortable with typing on crammed layouts. However, the KR-6600 is prone to miss the keys I'm sure I pressed, and occasionally the key press would register multiple times, leading to annoyances. I'm typing this entire review with this keyboard, and it's quite stressful. The tactile feedback of the keys are okay, so I'm guessing that the membranes that register the keys aren't quite functioning as intended. Maybe I'll check the issues with I-ROCKS soon.
These devices represent the cutting edge in the keyboard technology today and there sure are some rough edges. I look forward to some good fixes soon.