Bicycles are totally 20th century, tricycles are at least two years old depending on who you ask, and now all the cool kids on the block are pulling wheelies on their quadracycles – a feat all the more impressive because it involves getting two front wheels off the ground rather than one. Get with the times, check out TreeHugger’s 13 Cool Quadracycle Designs. We’re surprised they left out this smart yellow pedal-powered pickup though: