Acton RocketSkates R5 can hit 7 mph and are good for 5-miles on a single charge.
The skates are powered by dual 50W DC Hub electric motor. And they take only 90 minutes to fully charge.
There is also a smartphone app you can use to track statistics, map routes, to change speed settings, and even to remotely control the skates.
You can already get a pair here.
Via TechEBlog