What does that ISP think? Are they worried because MP3's are associated with music copyright violations? I presume they don't allow plain English text either, since it's just as easy to break copyright with that. And no pictures either! They can't allow graphics images - JPEGs and GIFs are alleged to have been used for child pornography......

All their customers websites must very boring - just a blank page. Still, I guess they load quickly.

Seriously...

WAV is so big nobody will download it unless it's very short clips. Actually 22kHz 8 bit mono is barely bigger that 128k MP3 but the sound quality is on a par with AM radio.

In case they are concerned that your MP3 creation software is breaking Fraunhofer's patents, (some progams are licenced, some isn't, some are in a grey area), OGG is good free software and I recommend you use that. Of course it will encourage anyone who doesn't have an ogg player to get one from