Horsemaning is The New-New Planking
Horsemaning is the New Owling, Which Was the New Planking
Planking is now two levels of played-out. First came owling (which is demonstrated by the vampires in Stake Land). Now there's horsemaning. (It's pronounced /HORSE-muh-ning/, and not /HORSE-MANE-ing/)
While planking and owling can be done solo, horsemaning requires a friend. one of you lies with your head out of view, and the other poses nearby, with only his or her head visible. Extra points for extreme mixing and matching.
Check it out; horsemaning hit The Today Show, which means that it's
played out mainstream.
Actually, horsemaning (as in "headless horseman") has been around since the 1920s... so horsemaning is the new owling, which was the new planking, which was the new lying-down game, which was the new horsemaning.
LOLcats are older than you think, too, but that's a whole 'nother story.