That's pretty tough. I don't know if there is a site that will allow that. Average 3-5 minute song is about 30-50MB. You can use yousendit but it's a limited time frame.

I bought a dot.com for just that reason and built a web site. The area on the back side of it that knowone can see is where I store my fires.

The best site I know for posting music and getting reviews would be Acid Planet at acidplanet.com, but they are wma files for your music sample and MP3 for the downloads.
The wma now a days can be rendered or uploaded as loss less but they will be just about as large as a wave and take as long to listen to or download.

The standared at acidplanet it between 64 and 96 sample wma because the it does not take very long for the song to start to play. this means more listens because people dont get frusterated. This is not bad quality for an internet streem all things considered and can be user friendly to dial up connections, yes they are still out there.

ITS A LONG WAY, TO THE TOP, WHEN YOU ROCK AND ROLL