Some years ago, I bought an Amstrad PPC640 off of a guy who thought it was "the first portable ever made". Got a good deal too, and the only flaw is that the screen hinge on one side doesn't latch well.
It came with what I think is MS-DOS 3.3 (it's been awhile since I played with it) and not really any software. I'm not entirely sure what kind of stuff I would even be able to run on a hard-to-read monochrome LCD screen. Maybe Digger? But look, it has a full travel keyboard: insane for a portable machine.
The whole thing folds up into a tiny little thing with a handle, which then fits into the most uncomfortable bag I've ever put a computer into. It's got a modem, plus parallel and serial ports, so maybe it would work with terminal software. It has 640KB of memory, an NEC V30 which roughly equates to an 8088, 8Mhz clock speed, dual 720KB 3.5" floppy drives, and the ability to put 10 C batteries in it to make it *gasp* portable. Apparently you can even plug in an external CGA monitor for 4 or 16 color graphics.
One day when it isn't in deep storage I will bust it out again and maybe try to run something interesting on it. Either that or I'll sell it to somebody who will love it, but that's not a concern right now.