Planking (or the Lying Down Game) is an activity consisting of lying face down in an unusual or incongruous location. Both 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. Planking can include lying flat on a flat surface, or holding the body flat while it's supported in only some regions, with other parts of the body suspended.
Here's some photo taken at my workplace.. enjoy..