If you’re a heavy duty Excel user, you probably have run into John Walkenbach’s Excel pages. He’s been helping folks figure out Excel problems for years on the newsgroups (if you’re new to newsgroups, Google Groups is a great place to start) and he developed a great add-in called Power Utility Pak. This weekend it’s on sale for super-cheap, and worth every penny. I used a copy back in the day and I think I’ll be buying a new copy now. There’s a free download too, but at $10 why miss the sale? Just take my word for it–it’s a bargain if you’re any kind of an Excel power-user.