Adam Bower writes:
You could get a 2nd hand Psion series 5mx (but they go for large amounts of dosh, I sold mine on ebay a year ago for more than i purchased it for in the first place) ok, it is only a b/w screen, but the keyboard is usuable and it uses AA batteries, I think you are limited to serial connectivity only though. Or (you didn't mention a budget) you could get a Psion netbook pro, which have a colour screen and are much larger and have built in USB, they also have pcmcia slots so I guess that you could connect a wireless lan card or ethernet.
I swap out my 5mx's CF card into a carrier and bung it into my notebook. Been doing this for years...
..Adrian