Scarpar All-Terrain Powerboard (video)
Basically its like a skateboard but with tracks underneath that are as wide as the board itself. A high powered motor drives these tracks and you hold a remote in your hand that control's the speed.
You can carve around like on a snowboard/skateboard/surfboard and the board can go over snow, sand and rough ground, if you watch the video you will see it concur an entire tree trunk !
scarpar.com has loads more info
They also have a Scarpar twitter and Scarpar facebook page
Watch the video !