It will work on any camera that has a SD memory card slot. You can also use it on a laptop, or a Wii system, as I have. Pretty much anything that has the SD card slot :)
Does it work with an MP3 player? I am unsure. But if you have a SD card slot, then it should. I couldn't give you an honest answer though, because I am unsure :( Sorry wish I could help more.. But if I had to guess, I would say yeah