Mp3 is a sound format.
The name in it's entirety is mpeg audio layer 3.
This stands for motion picture experts groups audio layer 3.
To play it you need either winamp or macamp.
Mp3 is used widespread for music piracy.
So, MP3s are disallowed on this free server...
The oth is the best.
for this and more Mp3 information check out...
They have software and search engines, very useful.
if you own a mac,
check out Macintosh Mp3 Information