Each year in the months leading up to the SXSW music festival, a massive collection of songs from participating performers gets assembled. The collection gets rolled up into a jumbo-sized torrent, and then given to the masses for free. The 2011 SXSW torrent packs almost four and a half gigs of musical goodness -- nearly 800 songs! The best part is that this is all guilt-free, legal-to-download-and-enjoy music.
If you're not keen on downloading the whole shebang, you can also listen to the included songs via Shoutcast -- all you need is a compatible player, like Winamp.