got to agree with you on the flat surface thing, Tonybro. it bugs me hugely that my stowaway keyboard has no rigidity, and needs a flat surface. when I set it up on the train, with the ameo behind it, the space it all takes up I might as well be using a laptop.
A couple of interesting and related gizmodo links from the last couple of weeks.
Nokia's patent for a virtual keyboard *without* using a projector
and
a very wee projector component from 3M, intended for mobiles. Its led rather than laser though.
Interface, particularly input devices has always struck me as a crucial area of PPC/PDA design. I'm currently favouring handwriting recognition and small full onboard keyboard, ala Psion5, HTC Shift, which obviously has an implication on the size of the gadget.
I still think there is mileage in a well designed, ergonomic chording keyboard like the twiddler, or possibly the frogpad, though that is primarily a one handed keyboard really needing a flat surface.
the Twiddler is currently out of manufacture, and there is a question mark over whether there will be a twiddler 3.
Both of these devices suffer from a very shallow speed/learning curve: My experience is that you can learn to type with the twiddler very quickly, but it takes a long time to build up any speed. You are supposed to be able to hit 40wpm plus, but I think you need to be very determined!