At least four vendors were offering datalogger computers built around 5.7" 640x480 active matrix touch sensitive colour screens. All of them looked VERY clear and easy to read. Three of them, which appeared to be cosmetic rebranding of the same basic unit, ran Windows CE with an extra data logging package, and had USB and networking ports built in, plus ports for sensors which you wouldn't need in a pocket computer. They didn't have a keyboard built in, but you could plug in any standard USB keyboard, including extra tiny ones. The package as a whole was too big to fit in a pocket, but that was partly because they were fitted with large rechargable batteries to power the sensors over several days, and partly for extra robustness - the casing was shaped for an easy grip without touching the screen, lots of padding, and so forth. Educational equipment takes a hammering.
Remembering that I just want something I can use to read ebooks, type notes on the train, go online to read my email, etc., and this looks interesting, as the missing middle step between PDAs and netbooks.
Take that screen, or something the same size but higher resolution, and build it into a casing about the size of a paperback book or a DVD case. Give it a gig or two of RAM and SD storage, a reasonably fast processor, bluetooth and wireless connectivity, and you'll have a very interesting little PC. To make me REALLY happy give it a keyboard, but I'm not too bothered if it's a plug-in extra provided it's a standard USB type.
There are probably already industrial computers with a similar sort of specification, but as far as I know there's nothing on the general market. And that's a real shame.