Sporting-Sails for skateboarding

I just got one of these sails and tried it out for the first time skating late yesterday afternoon. It's mainly used to slow down when skateboarding downhill. Fun! I'm still getting the hang of it, but I was able to go down some hills where I'd normally get going too fast and have to jump off.
Two women came around the corner when I had the sail deployed and one said, "Oooh that looks like fun!"
I also tried it out last week on my paddleboard, sailing with the wind.

http://www.sporting-sails.com/