Nah, don't bother trying to convert .mp3 to .mid, it is possible (haha Raven

) - you can convert the .mp3 into a wave file, then there's programs that analyse the sound wave and convert it to a .mid file. This is only really used for analysing notation though, not really a conversion.
Don't know if your aware that .mid files are more similar to tracker songs, they don't use sampled sounds, rather rely on your sound cards hardware or any midi equipment you might have connected (like a synthisizer). .Mids are really small and convenient, but getting good tunes is tough, most are fairly badly put together. The best .mid tunes I've heard were from Dr. Awesomes website - check out TGC newsletter 10 for an interview with the very man and website link - on his website you'll find several .mid songs. Be sure to ask him before using any of them though, sure he would'nt mind, but you'll probably end up using a lot of them - so a website link, or maybe even a full screen add in your game would keep him happy.
Van-B

I laugh in the face of fate!