I was futzing around on the iTunes Music Store podcast section and saw iLike promoted there (didn't follow through), and then last night a new friend on Facebook shared the iLike application with me (followed through).
I've found iLike to be a clean, simple interface to show the music I enjoy, see what my friends enjoy, find new artists based on my taste and play the time-sucking iLike Challenge, a game where you listen to snippets of tunes and have to name the artist or song. On the Facebook app, after selecting or entering the names of the bands you like, you quickly see not only whether the bands are touring, but whether they're coming near you. Indicate you'll be at the concert, and you get a list of all the other Facebookers that'll be there with you.
Later this weekend, I'll install the iLike sidebar for iTunes and see where it takes me. If you're into music and want to map your tastes to those of your friends, give iLike a spin.
On a side note: I can't believe how much I've enjoyed diving into Facebook since they opened the platform. Find a lot of interesting new things and people, which is why I play in social networks anyway, right?