If you like Internet radio and you haven't heard about Pandora, I recommend you check it out. It's a Flash-based, Web 2.0 music player that works like this:

• You tell it the name of an artist or song that you like.
• Pandora analyzes the qualities of that song (or, if you entered an artist, one of their songs that it randomly picks) such as instrumentation, rhythm, etc.
• Pandora compares your song with others that have been similarly tagged in the Music Genome Project and creates a station for you based on the inherent musical qualities of your song.
• As you listen to your station, you can add more songs for Pandora to base the music off of. You can also tell it if you like a song it is playing or don't like it. If you don't like it, it will never be played again.

Before Pandora, I had been listening to Yahoo! Music often.  But Pandora is better because:

• There is no audio advertising, just a visual ad on the page itself. This is so much more pleasant than being interrupted every 10 minutes on Yahoo to listen to that same Vonage commercial over and over again.
  
• You can create multiple stations. This is especially important right now because I'm listening to Christmas music. On Yahoo, I could listen to Christmas music and rate it, but then it would get lumped in my one station and keep coming up all year long. On Pandora, I have a separate station for Christmas music playing just what I want to hear. I also have separate stations for my rock, my hip hop, and my mellow stuff.

There are some limitations to the service right now (doesn't have classical music (sorry Sheri), sometimes lags when you tell it you don't like a song, etc) but I'm sure it will only get better in time.