The Freesound Project aims to create a huge collaborative database of audio snippets, samples, recordings, bleeps, etc. released under the Creative Commons Sampling Plus License. The Freesound Project provides new and interesting ways of accessing these samples, allowing users to:

• Browse the sounds in new ways using keywords, a "sounds-like" type of browsing and more.
• Upload and download sounds to and from the database, under the same creative commons license.
• Interact with fellow sound-artists.

If you have audio samples which can be released under the Creative Commons Sampling Plus License then why not get involved and add them?

NOTE: They are not looking for songs, or compositions. They are looking for sounds. Field recordings, kit recordings, generated sounds, etc. as long as the sounds are not copyrighted (in a non-compatible way) or if the sounds are made by yourself and you want to release them under the Creative Commons Sampling Plus License.