Are you almost over the hill? Know someone who is? Getting older is no fun, but it sure can be funny. How do you know when you're approaching the big 4-0? Here are a few clues- * Comb-overs are starting to make a certain kind of sense. * A kid you once babysat for is now your lawyer. * At your checkups, the doctor has begun to ask if you're still sexually active. * Midnight seems awfully late. * You're more interested in websites that will calculate...