Colin Kaepernick led the 49ers past the monolithic Green Bay Packers on Saturday night with a record-breaking performance. After scoring a touchdown Kaepernick "kissed" his bicep.
This was quickly adopted by the Internet as "Kaepernicking." Posing for a photo while flexing and (ideally) kissing your bicep, though some just flex and look at it. Regardless it's better than Tebowing.