The Freesound Project – a collaborative database of Creative Commons licensed sounds. It is developed for the international computer music conference 2005 to be held in Barcalona Spain in September. The site has a very advanced search engine. The best was recently introduced: geotags were added for the field recordings in the database. This means that you can look at your google earth and see all these cool sounds from all across the globe. Thanks Anton! Link.
The Freesound Project