ChaosKnight has released the worlds first Apple Macintosh emulator for the PSP, the port itself is of the Macintosh emulator Basilisk II, heres the info
What Works
Emulation
Video (wrong colors, slow)
Input (start = return, mouse = analog + X = click)
What Doesn't
Ethernet
Audio
Keyboard
External Filesystem (ability to use flash0:, mc0:, etc...)
Serial (no irda0: support yet)