I have just bumped into this website today. I thought about sharing this with my fellow HTGTH members cause we all pretty much share a passion for music.
Ok, you can use the site to broaden your musical and movie backgrounds. What you do is you type in a band on the search bar and a map will open with all the bands that are related to the one you've typed. This is cool cause it opens a wide horizon of other different bands you might be interested in.
Also, each band is circled by a colored halo. The bigger the halo is, the more popular or representative the band is. This is very subjective, but it gives you an certain idea of how this site has ranked each band.
By the way, the GNR halo is not that big...
You can do the same thing with movies & directors. You type in "The big Lebowsky" and it gives you a map with all the related movies in taste to the one chosen.
http://www.liveplasma.com