Would it be possible to make Project 64 (a Nintendo 64 emulator) portable? I know for a fact that it writes settings to registry, thereforer it's not fully portable. It'd be nice to play N64 games from my thumb drive. Of course, I'm not sure how fast they'd run off it, but that's something else altogether.
I also don't know if it's open source or not, so maybe it's not possible to portable-fy it. Unless someone has a suggestion for a different program, but I searched for one here and found nothing.