If you've never heard of Speed Stacking, where have you been? Ellen Degeneres has talked about it on her talk show and it's about to go just as viral as Rainbow Loom.
Speed Stacking is a sport where you arrange specially-designed cups in a specific order at lightning speed. Literally. Lightning speed. M rounded up some of the craziest (and of course, fastest) Speed Stacking YouTube videos so you could see what the sport's all about.
Tell us in the comments: Would you ever try Speed Stacking?
Speed Stacking Girl