Pandora and Last.fm

I trust you're already familiar at least one of these online music services, pandora.com and lastfm.com - if not, you've got a treat in store for you. They're both web music streaming services that offer a superb way to listen to your favorite style of music and discover new artists. Pandora was the first one I got turned onto - you simply enter one of your favorite artists and pandora constructs a "radio station" around your choice, selecting songs by the artist you entered and ones that share the same characteristics. I have 10 or so radio stations on my list, and the database includes a respectable selection of even out-of-the-mainstream world stuff that I like, such as Japanese and Brazilian pop and glitch. I've created a mix called Drum Thunder Radio, "seeded" with my favorite drummers: Williams, Cobham, White, Chambers, etc. There are some gaps, but Pandora seems to be working to fill them, constantly enlarging their database. Lately Pandora has been featured in the Doonesbury cartoon strip, with soldiers in the Iraq war making "battle mixes".
Last.fm is similar, except it takes a more extroverted, social networking approach, and it scans the resident music player on your computer in order to tailor its playlist to styles that you like. I know that at least Pandora has endured legal challenges by the recording industry. I don't really see why—you cannot permanently download songs, and if anything they might stimulate the listener to go out and purchase some of the music that's discovered. Anyway, check 'em out.