Who was the retard that invented planking?

I was on Twitter, and I saw a twit from NFL football start, Michael Oher on what is #planking? To my curiosity I look further into planking and saw a bunch of idiots laying flat down on doors, side of the road, on the Wal-Mart register, etc. Heck I even saw Chris Brown planking and a man planking a pig. What is the purpose of it? And is it suppose to be a joke? It looks retarded to me, as if ppl don't have anything else to do with their time. I main question is who's the idiot that invented planking?