You were expecting this weren't you? Although some of the other ones weren't exactly 'geek tools' (email and web surfing isn't geeky any more, is it?) there were a few others I didn't post about;
WinAmp - My MP3 player, streaming, ripping, tool. I love the "make a mix based around this song" feature that was recently added.
Pandora - Great site for listening to music you may not normally hear. Configure to what you'd like to hear and let it go. (Although I haven't used it, heard a bit about last.fm servers were down when I went to check it out)