Just picked up one of these...
http://en.wikipedia.org/wiki/DingooBasically it's an open source handheld with a great little screen and built in emulators. Impressive little thing to say the least. I haven't updated any of the firmware / software or anything yet (the community is thriving and updating it all the time) and have happily played the likes of Super Double Dragon on the move with next to little complaint! (SNES emulator drops a few frames but it's still very enjoyable depending on the game). I can't wait to update the emulators!