We7 is a great way to preview, vitualize and buy songs online. You can only listen to 30 second samples, but at least you can download mp3s as opposed to iTunes m4ps.
The website states, “We7 is an outstanding new music destination where you can listen to, share and discover music for FREE, legally and safely. You choose the music you want to hear and play full songs and albums online, on-demand at anytime. We also offer you the ability to buy the music you love in high quality mp3 downloads which you can play on iPods and most other digital players.”