LaLa has come a long way since its original inception as a music locker and discovery service. Now, it's a full-on music service that lets users listen right inside of the browser. It blends a discovery engine with an online marketplace to let you explore new music and buy MP3s for playing offline. Better yet, the interface is super clean and simple, which means that anyone can play without having to know the intricate ins and outs of a overly detailed online jukebox.
The original functionality is still in place: LaLa scans your hard drive for music and then ports your entire library (really, copies of tracks it knows you own) to a "cloud." You can then access this cloud from any computer that's connected to the Internet. If you have tracks in your library that don't exist in the locker service, you can choose to upload them so that they are accessible as well.
At the moment, LaLa is most famous for its paid streaming service, where users can stream any track once, for free. After that, 10 cents gets you the rights to stream it as much as you want, which covers the license and the cost to get it to you. The caveat is that you don't get to own the song outright, but it is a whole lot cheaper than a la carte downloads. And now that LaLa has an app on the iPhone (and iPod Touch), accessing the service from just about anywhere on-the-go is a whole lot easier. If you're looking to broaden your musical horizons, definitely give this one a look.