Valve have released Volume 1 of the soundtrack from Portal 2 as a free download, further cementing their awesomeness:

Whether you're a mega-science corporation with decades of test experience, or a young start-up liberating your first test subject from non-testing with a chloroform-soaked rag, Aperture guarantees results. Wake up your test subject, open the chamber door, and press play--let Aperture's patent-pending rhythmic compliance enhancers do the rest.

In addition there's a bunch of ringtones available from the official site, if that's how you roll, but otherwise you can just download the soundtrack in its entirety now locally from AusGamers.