KEXP Archive is a very cool HTML5 application that uses the KEXP dataset to show off a cool visualization. The KEXP data set represents nearly 10 years of radio playlists and includes over 700,000 tracks with album art, the date and time each song was played, and DJ names. The result, created by Stimulant, can be seen at http://kexparchive.org. Pretty rad.
This application was featured in the IE9 launch at SxSW -- watch it demonstrated in a video here. Also, it was shown while KEXP broadcasted live from SxSW at Mellow Johnny's, Lance Armstrong's bike shop. Here's some pics of the KEXP IE9 kiosk in the bike shop: