http://freesound.iua.upf.edu/index.php

In preparation for the International Computer Music Conference to be held in Barcelona in September 2005, the Music Technology Group and the Universitat Pompeu Fabra, have created the freesoundproject. The freesound project is a collaborative database of sounds – not songs or compositions – but sounds: audio snippets, samples, recordings, bleeps. All sounds uploaded to the site must be licensed under the Creative Commons Sampling Plus license. The site has already collected a range of diverse sounds – from instrumental pieces to balloon sounds – and offers sample packs, remixes and groovy waveform images of the sounds. A great example of building out the creative commons!