bitsandpieces

a free online file conversion site which supports four categories — document,
image, music/audio and video. You upload a file from your hard drive,
use the dropdown menu to indicate which format you want it converted to
and, when it’s ready, you’ll receive an e-mail with a live link you can
click on to download your converted file. The link will be good for 24
hours.

http://www.zamzar.com/