here's a couple common music sharing sites (some might even take WAV):
http://www.soundclick.com/default.cfm
http://www.esnips.com/
Then there's just file exchange sites......
http://www.sendspace.com/
http://www.megaupload.com/
or maybe even make a Youtube video of it
http://www.youtube.com/
if your not using iTunes, it'd be worth downloading just for the convenient conversion to MP3 feature. Just click the song > under "advanced" click "create MP3 version".
g'luck