Try Hula Hooping (420–600 calories)
Chances are that you weren't thinking about improving your muscle tone when you shimmied in your parents' backyard, but a recent study by the American Council on Exercise found that intermediate-level hula hooping can burn as many calories per minute as step aerobics, boot camp (atten-shun!) or brisk walking. The humble hoop can tone the abs, back, arms and legs as well as improve balance and flexibility. As with any exercise, you only burn significant calories if you can sustain the activity, so to get maximum fitness benefits, upgrade to a grown-up hoop from Hoopnotica. At 1.5 pounds, it's slightly heavier than the child's toy, and weighted hoops are easier to keep aloft. Hoopnotica also sells DVDs that can teach you some basic moves to keep you busy (the "one-handed halo" makes us feel like a hooping Hindu goddess).