For the aspiring hacker, we've also got:

The 80's/90's VeriFone Tranz 330 credit card terminal, which has a complete Z80 computer inside with DART, CTC and PIO chips, 32K RAM, and a socketed EPROM.

The Cidco Mailstation, which has a Z80, sizable monochrome LCD, and full-ish size keyboard, perfect to hack into a TRS-80 Model 100 style laptop.

You can pick up either on Ebay right now for ~$25