Spoiler: Go-Ped Knightrider
Look at the Go-Ped Knightrider on this page if the above picture no longer exists! It's got a motor that allows it to travel at a top speed of 17 mi/h and a lithium-battery that lasts for 25 mi.
It's the closest thing I've seen IRL to Conan's solar-powered skateboard! I kind of want one. Sadly, it's a little expensive.