What should I blog about?

Why have a blog if you don't have anything to say? Who really cares, and who really reads these things? I hear Curt Schilling from the Boston Red Sox has a blog. I've never read it, but I guess people do. Now, if Ozzy Osbourne had a blog, and I knew 100% that he wrote on it - THAT might be a blog I would read. Probably get a laugh or two out of it at least.