That sounds pretty cool, I'll have to try that one. That's not what Satch is doing though (at least I don't think so). I'll try and explain it better.
He wraps the webbing of his right hand, between the thumb and first finger around the neck of the guitar (he moves it between the 6th and 2nd fret)
At the same time he hammers on arppegios w/the left hand. The arp[egios are not played on the same string like he usually does, but instead are played across the neck. It's hard to describe the sound he creates when doing this but its pretty cool and very impressive to watch. Any Idea?