I have been waiting for today for a LONG time.
Several months ago (in fact, about 15 months ago), I heard of a site that was going to offer free music downloads, based upon advertising. While the site is brand new, www.spiralfrog.com is up and running with free music downloads.
I don't have an mp3 player (iPod or otherwise), but these songs can be downloaded to your computer for use in many ways (burned to CDs, mp3 players or just listening on your computer).
I hope you enjoy this new service, and I hope it saves you some money on music. Downloading, even at about $1 per song, can add up really quickly into a way to burn through a lot of cash.