Yesterday on Korean TV, I saw somthing like this:
http://www.gadgetmadness.com/archives/20050321-the_roller_cycle_personal_power_accelerator.phpBut it was in front pulling the skaters on the highway.
I've done all kinds of web searches and haven't found anything about it.
Several of the people were using large wheel inline type skates and one man was using a much longer 2 wheel board with large wheels.