gp32 is a "psp" type handheld which is open source and allows emulators, music, movies on it
there is a new version out - gp2x which runs on linux and already has a nice array of emulators running (snes,megadrive, nes, gb, mame etc)
the gp32 still has a small community, but most moved to the gp2x .
Both machines are excellent for homebrew games,apps,emulators etc
im going to buy a gp2x in the coming weeks, costs $200
go to -
www.gp32x.com for some info on both