I wanted to make a ring tone last week from audio on a youtube.com video.  I've written about free online ringtone creation before, but that requires an mp3 file.  That's where Zamzar comes in.  Zamzar offers free online file conversion from many formats into many formats for files up to 100MB.  (You need to sign up for a paid subscription for conversions of files from 100MB to 1GB. Just upload the file, pick your file output type, and enter your email address. Zamzar sends you an email with a link to download your converted file.  Easy peasy.