[LAU] Audio to midi, finding notes from an mp3

[Simon Williams]

Does anyone know of a program which will convert audio to midi?
Maybe that's a little ambitious. What about something that will show 
which notes are being played or what key the audio is in?

I have some mp3s which I want to play along to, but I have no idea what 
key they are in or what notes are being played. The tracks move too 
quickly for me to pick out the notes.

If all else fails, I need some way of sanely repeating a short section 
of music so that I can try and find the notes myself.

Any ideas?
Thanks
Simon