I've seen and used one. I'm planning on buying one in a couple of weeks.
they are about the same size as a pocket PC, and have a built in Qwerty keybooard. The keyboard is very usefull and speeds things up greatly. They also have two expansion slots. They have a 16meg rom where the OS is kept and 64 megs of ram for everything else.
The software is great also. It runs Linux with kernel 2.4.x, and Java. The programs all start up nice and fast, and respond well too. It comes bundled with Opera and Hancom Office. Hancom Office lets you read and edit MS Office documents. As funny as it seems it is possible to run X on this, althougb it is not easy. And if you were truly insane, you could set it up as a web server(it has been done).
There are only two things I didn't like about the Zaurus. The Image veiwer sucks(but Opera can be used for this I suppose), and the music player needs work(but replacements are available).
All in all I'd give it a 9 out of 10.
