I just did. The Rockboard RBX Scooter.
Video courtesy of Thrifty Mom's Reviews
Basically, it's a scooter that uses a rocking motion to propel it. I personally think this would be great cardio. And since it holds up to 220 pounds (not bad for a scooter,eh?) I could totally borrow it. Maturity be damned.
For a full review, go to Thrifty Mom's Reviews HERE.
If you're also now fascinated and eager to make your kids' (or your own) day, you can enter to win your own right here!