Yet another meta, but included due to Mamma's popularity. This is about the coolest visualization tool I've seen, based on ODP data. Nothing special except for popularity. Don't know anything yet. I don't know much about PowerSearch yet.
Some folks think this'll be like web addresses someday.
People use it. You can use this site to influence DirectHit data. Sprinks Surfwax Meta searcher that will list your competition alphabetically. Now uses Excite's data. WebTop WebTop is supposed to have a big database.