I discovered Muxtape and I think it rocks.
First off, you get to listen to other people's mixtapes and we all know we love to do that! The mixes are eccentric and they highlight songs and artists that I should hear. Plus, the site is about as basic as you can ever imagine. No images, no social networking, no emails to register for. Just text and music. Its black and white, until you change the colors. And oh yeah, it's free!!!
I HIGHLY recommend you go listen to it.