Lala.com
Lala.com, a former CD-exchange site, has reinvented itself as a music shop that lets you sample the goods for free, and not just 15-sec previews but entire albums—specifically those owned by Warner Music Group and hundreds of smaller indie labels. The company hopes its largesse will lead to more sales; you have to buy a song if you want to download it into your mobile device. Bonus: Lala's songs will play in your iPod, a first for an iTunes competitor.
Lala has its own music player for you to download, but you don't have to use it to listen to the free tunes; you can listen from inside your browser. But if you register as a user and download its client, Lala can scan your entire digital music collection, upload what it doesn't have in its own library, then make your playlist available to other users—and to you whenever you log in away from home.