I've been toying with a Playstation Portable emulator for the past few months (but only for about 4-5 days a month total). I finally got it rendering graphics now! It supports some basic BIOS routines like file IO, threading, events, timers, controller input, and now basic graphics support. I also have a fully dynamically recompiling CPU that translates the PSP's MIPS instructions in to .NET CIL instructions - I believe it's the first of its kind!