Work out a limb, any limb Hobie Mirage Revolution: Speedy, 13-foot, 5-inch performance kayak with pedals that drive two underwater fins that work like a penguin's flippers. Likes: Exhilarating fun. No learning curve. Faster than a regular paddled kayak. Seems effortless (until you climb out and feel the burn in your thighs and butt). Anyone of any age or skill level can push the pedals, which move back and forth (not circularly, like on a bike). Steering is done by a small left-side lever. Otherwise, hands are free. You can also paddle it like a normal kayak (the paddle is attached to the side) or do both at once -- a tremendous workout. There are many convenient design features: pop-off wheels that neatly stow behind the seat, water bottle holders, a hole for a sail mast. Dislikes: None Price: $1,649. (800) 462-4349; www.hobiecat.com.