That's amazing Dave who would have ever guessed that?http://www.youtube.com/watch?v =tHJKKdEo8TQXX
The sailing rocks in California. Big rocks that move by themselves, and pretty straight.
Read some of the stupid theories such as wind and ice. In the league of log rollers for pyramid building.
Pure EM and piezoelectric effect. The piezoelectric vibrates the sand, breaking friction. However, there is something above or below steering it, perhaps even tidal forces.
You can push megatons horizontally if you have no friction. You just have to overcome inertia.
Bur you have one slight problem with your hypothesis, and it's pretty hard to deny. It's been solved exactly how they move
and caught on video.