I know you asked for a free site, but I doubt there is one that will let you hotlink to thier files for free. For just a little bit of money, you could have your entire site (MP3's and all) completely hosted. ($10-25 a year) No banners, no ads. If your interested, I can give you a few places to look into.
And, as always, if anyone wants songs hosted for review in the MP3 clinic, I will host them for free, just email me at -