I want one :O
Video
A woman demonstrates riding a zebra model of a "Rangs Eco Pony" at the International Tokyo Toy Show 2011, in Tokyo June 16, 2011. The pony does not require batteries to move as it relies on the momentum of the rider bouncing up and down. Each "Rangs Eco Pony" price is 92,400 Yen ($1200).
Video
"This toy is called Eco Pony, and all it needs to move is children's energy." - Miki Kobayashi. CEO, Rangs.