Zamzar

Zamzar is a website which can convert practically any file format into another file format without any need to download software. It can convert between five image formats, 14 document formats, 11 audio formats, and nine video formats.

After you've selected a file or files to convert, Zamzar will tell you which formats are available to convert to. Then you supply your e-mail address and click "convert" and Zamzar will e-mail you a link to the converted file.
www.zamzar.com