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 your Body Mass Index than in Internet porn.* You receive two phone calls in a single week from people who want to sell you life insurance.Whether you’ve just found your first gray hair or you’re peering around the corner to your mid-life crisis, You Know You’re 40 When… will tickle your funny bone (while you can still remember where to find it).