Mac OS 7.5.5 on the PSP
This chick installed BOCHS (an x86 emulator) on a Sony PSP. Then she installed FreeDos and Basilisk II/vMac (Mac 68k emulators). Sure it takes 4 hours to boot, and has no keyboard/mouse support, but it's still damn cool. She should have taken it one more step and installed STELLA for some Atari 2600 action!
All the required files are available from her site as well.
(Thanks Oldies)
-CGP fo Life-