For those who do not know what planking is here is the wikipedia definition:
“Planking” (or the “Lying Down Game”) is an activity consisting of lying face down in an unusual or incongruous location. The hands must touch the sides of the body and having a photograph of the participant taken and posted on the internet is an integral part of the game. Players compete to find the most unusual and original location in which to play. The term planking refers to mimicking a wooden plank. Rigidity of the body must be maintained to constitute good planking.
Since early 2011, many participants in planking have photographed the activity on unusual locations such as atop poles, roofs and vehicles, while some “plankers” engage in the activity by planking only their upper body and feet while leaving the back suspended.
Some plankers have taken to the extreme by taking pictures of themselves in a planking position in crazy locations.