I am tempted. I have a little experience with this in a school setting, but not from a technical rip-one-open-and-resuse perspective.
The thing is, it's rumoured to be able to run embedded Linux and it does have RS232 serial communications, a full keyboard and small LCD display, as well as battery. Even "as is" they make nice little typing tutors for kids, but it does have a data transfer function and I think it can also act as a serial terminal. This thing BEGS to be married to Arduino.
They are available used all over the place, school systems used them extensively until "real" computers entered the classroom. They can be bought cheap, are tougher than rocks, and seem too good to be true as even a serial terminal for I/O to projects... You could even piggyback on the internal battery for Arduino power. If this can act as a basic serial terminal, it's more than worth it's price!
Thoughts or experiences?