has anyone tried these? http://shelter-systems.com/gripclips/

The price is right and I like the look of them better than the others I've seen. I like that they suggest using a cut out scrap of a balloon to keep the nylon from abrading; might be easy to put a scrap on each side of the tarp to keep the edges of the plastic padded.

Anyone used these? was thinking of adding one or two to each side of my tarp once in a while.