If you make music, particularly music on your computer, or using samples, then you may be interested in the SampleSwap website. SampleSwap offers free professional audio samples without advertsing. The samples are available in the .aiff format which is easily convertable into .wav format for those still using windows.

At the time of writing SampleSwap’s collection is currently 4.6 GB (9,823 sounds) including 1,860 techno, hiphop, trance, and drum ‘n’ bass loops / breakbeats, 2700 drum hits, 2040 sound FX, 570 instrument samples, 810 vocal samples, 748 melodic loops, and more.

The site has a forum which includes useful tips for music production, music contests and other cool stuff.

UPDATE: They now have an iphones site for your enjoyment: “You can now listen to music by SampleSwap artists on your iPhone at iphone.sampleswap.org

Very nice!