(UPDATED) Mixcloud, which hosts half a million radio shows and DJ sets, is now sending their audio to Juno Download to be analyzed and identified. The goal is to enable accurate matching of tracks which have been mixed together and pitched up or down in the mix by using their database of 4 million tracks.
The tracklist data is then sent back to Mixcloud alongside start-and-stop times and "buy" links. (Note: By comparison, iTunes has 12 million tracks in its library.)
Here's a sample MixCloud player:
