This homebrew offers full speed emulation of GameBoy and GameBoy Color on a PSP (much like Homer's RIN or GeMP). That's full-speed fps for all GB and GBC ROMs. Not bad for a day's work; it was tweaked from InfoBOY (a Win32 GB/GBC emulator) in less than a day.

There are a few limitations:

* There's no browser. You have to manually replace the rom.gb file.
* Sound is not synchronized with the emulation.
* Some users report color changes.
* No savestates.