ok.... i vaguely remembered that there was a cool site that BBC Click Online reviewed. after doing some searches:
http://www.last.fm/
this is a newer version of the website (used to be audioscrobbler -- see below). based on collecting data on what people actually listen to, they did some correlation analyses. type in a band name, click on "find similar artistis" and/or "see more similar artists", and there you go. i did this with "the black crowes", and the list they came up with was about 90% of stuff that i know that i REALLY like.
http://www.audioscrobbler.net/
this is the back-end that collected all of the data for last.fm.
http://www.pandora.com/
nifty site similar to last.fm.
http://www.allmusic.com/
great music site in general. if you look up a band, they have a TON of information including similar artisits, see also, influenced by, and followers.
http://www.pcworld.com/article/id,12353 ... ticle.html
year-old article that may or may not be interesting.
http://news.bbc.co.uk/2/hi/programmes/c ... 707239.stm
the motivation for this post.
hope this helps.