John Currier, a former CharJUGger, released a tool a while back called Schema Spy. If you haven’t seen it, you owe it to yourself to check it out. It generates graphical dependency diagrams of your database, including things like implied constraints between tables.
Anyway, he sent a post over to the CharJUG mailing list saying that he was trying to figure out why he was getting so many hits to it, and then realized it was listed on the front page of SourceForge, and was ranked #54 out of 114,000 or so project!
Congrats John, and check out Schema Spy!