So as a training/fun project I made my own build of goboy gameboy emulator for s60. Why? well, the new gcc tools available offer much better optimizations.
Here is the project page with .sis and .zip to go. It's not without it's problems though, saving only works up till slot 8(well, saving works but loading doesn't) and there is no sound support(exports not getting frozen I suppose like they should be or it's intentional from wildpalm, it looks like slapping another soundserver on it wouldn't be that hard though). However, the speed gain is well worth it(also demonstrates the optimizing power of the new tools pretty well in my opinion).