My experience with last.fm and pandora have been fairly lackluster. The one band/CD I found was ... JaR -- Scene 29 ... which is a Steely Dan Aja / West Coast AOR band. I highly recommend, btw. I do read some music boards like at Melodic Rock.com, here. There are mostly Euro posters, but they talk about a mix of American and Euro acts. I found many great bands there, like PC 69, Pretty Maids, Gotthard, etc. Lastly, about twice a year I go out to the Usenet groups, spend an afternoon and download a bunch of random stuff. I end finding bands that I heard of but had not really listen to, like Robin Trower, The Rascals, The All American Rejects, Tonic, etc.
I'm usually searchin the Amazon New Releases and "Customers Who Bought This Item Also Bought", find pretty much anything there that fits my taste.
YouTube and iTunes. Maybe you could also post what artists you like on here and someone might recommend something.
I might have overstated this a bit. Listening to radio stations on last.fm and pandora have not led to much. Last.fm does have the concept of "neighbors", i.e. people who share some of your tastes. I can read these neighbor's profiles to see who else they like. From my neighbors, I have stumbled on Yellowcard (like) and Jason Mraz (OK).
Something that I have done for books but not music is to surf Amazon's Listmania. Oversight on my part.
Even though I have over 3TB's of music, I still use grooveshark when I don't feel like going through all of my music. I still learn about most new music via Sirius though. Even when Stern retires I will not be getting rid of it, ever.
All Music has a page per band/artist. On that page, they have a list of artists/bands that are Similar Artists, Influenced By, and Followed.
