Your creative ways to say "none of your business"?

I'm curious of what other people say when someone (say, a coworker or a complete stranger) asks prying questions-- or even questions you just don't feel like answering!

Personally, I enjoy giving irrelevant answers to the busybody I run into at least once a week, from the classic "I'm going to iron my dog" (more of an excuse, but still great for befuddling), to the recent favorite: "This human suit is chafing and I need to remove it to apply baby powder."