I just released PSPUAE, a port of UAE to the PSP. It runs at about 75-80% of a real Amiga 500 speed but some games are definitly playable like E-Motion or Rick Dangerous.
Oh and it's very alpha as it doesn't have any menu yet...
-Added disk selection
-New icon and background image courtesy of Fred Holgado
-You can now install PSPUAE in any PSP/GAME folder