Web 2.0... that mysterious... substance... beautiful... useful... fun... but... what is it? Well, honestly, other than great graphics, high-tech, and user interactivity, I'm not sure myself. But here's several websites that compile lists and directories of this strange new phenomenon, so even if we don't know what it is we can still have a great time surfing through it!

http://www.allthingsweb2.com/

http://www.go2web20.net/

http://www.seomoz.org/web2.0/short