Definitely a very cool site, and built by some very classy folks at Perfect Game. I got to meet Rick Stephenson in person this spring at my son's college baseball game, what a nice guy! (Rick does a ton of the video work on baseballwebtv.com and also produced the now famous Showcase and Prospect movies.)
I have not had as much time as I would like to visit the site and keep up with their new additions, but you could spend hours and hours there checking out player videos, showcase games, etc.
Warning: It could be addicting (like this site)!