"Planking" Replaced by "Horsemaning" According to Bored British Journalists

Old Internet Trend: Lying still in imitation of a stiff, lifeless plank

New Internet Trend: Lying still with a friend so you appear headless

The term "horsemaning," often spelled horsemanning, comes from the headless horseman in Washington Irving's The Legend of Sleepy Hollow.  Though slightly more creative than planking, horsemaning will surely become ever present on social media sites before the inevitable tragedy.