For those of us who enjoy taking advantage of our gray-area legal rights, there are two websites which aggregate DRM-free mp3's which have been posted on various music blogs and sites for download:

Skreemr

and

ProjectPlaylist

For the project playlist site to work you must have your browser useragent set to the iPhone/iTouch string

ProjectPlaylist also supports the creation of online playlists that you can listen to from your browser wherever you get internet connection (visit the non-iphone version of the site for this) utilizing a flash player.

Anyway, enjoy listening and make sure and pay for any music that you appreciate!