If you're a runner looking to burn more calories or increase your speed, you've got to try a Nike Parachute ($50).
The effects are similar to running in water or on a really windy day. Basically you strap the belt around your waist and as you run, the parachute catches air and adds resistance as you move. The faster you run, the more drag you'll feel. It can cause up to 15 pounds of force pulling you back, so it makes you work harder and increase your stride. That in turn makes you an awesome sprinter or a faster long-distance runner. Tyra Banks uses one because it's a great training tool, but I'd definitely stick to using this on a track or sports field. Running with a parachute in your neighborhood probably isn't the best idea.