Tunes
Here's what I've been listening to lately, courtesy of a Last.FM data feed. You can see my whole Last.FM profile and check out my Pandora stations. Slacker doesn't offer profile pages (or data feeds) yet, but it's still cool and worth checking out. Like the rest of this site, this part could use a little design love, but it's on the way.
Geeky details: I'm parsing my Last.FM "recent tracks" XML feed to get the artist, song title, and album (since tracks can appear on multiple albums, Last.FM is using their best guess as to which album the track is from). If Last.FM doesn't know the album, I do a lookup for it on MusicBrainz based on the artist and track title. Then I pass the album name and artist to the Amazon ecommerce API to get back the album cover art and a link to buy the album on Amazon. I am also doing some custom caching to reduce the number of API calls.
Create a Pandora station based on this 
Listened at: 5:25 PM on Wed, Aug 27, 2008
Listened at: 5:22 PM on Wed, Aug 27, 2008
Listened at: 5:15 PM on Wed, Aug 27, 2008
Listened at: 4:54 PM on Wed, Aug 27, 2008