I never get tired of internet services that define me by my tastes. The reason I got into LastFM was because someone else had the widget on their blog and it looked cool. It filled me with a burning desire to have my favorite songs streaming here on Odd Obsession. It also lets me broadcast my soundtrack on Facebook. I don't really use it for recommendations, though. For that, I'm still a bit old-fashioned in using radio, albeit of the Internet variety (it is handy to have all the tracks listed. Listening to regular radio and having to wait for the DJ to say what they're playing seems so frustrating now, doesn't it?) Another hint from Dr. S is searching for lists of bands under a genre like "Stoner rock" on Wikipedia, then going to SeeqPod or MySpace to listen. Really the only reason for MySpace to exist.
Anyway, for those with a lot of time on their hands, LastGraph offers a lovely visual representation of what you're listening to. I was loving the Hives and stoner rock, wasn't I?