EW's "Must List" gave a plug to this website
http://www.bandtoband.comwhich connects bands to each other (using "family trees" of each band)
a la "Six Degrees of Kevin Bacon." From their home page:
"Bands have a tendency to share band members from time to time and as a result it is not difficult to construct a simple "family tree" based upon the interrelationship of band members. We at BandToBand.com decided to find out how large this extended tree is and the following list of bands is that result. Each band listed below is connected to every other band listed based upon this family tree principle."
Very useful! Hours of fun!