I may repit something that has already been said, but... this is making my mind crack! As said in the the series, bending comes from the legs, from the energy that comes from the Earth (planet or Element, i dunno). "What what about Katara when she jumped to the air and attacked the Earth Guardians at the palace?" yeah ok. But now, physicly talking: to a force, other oppose. you could lift a box, because while there is the force of you pulling it to the air, there is the force of the box pulling you down. This... Levitation thing... thats like a marionet pulling itself into the air! I won't bother you with this anymore, but here lies my opinion: you cant levitate yourself, you are not laghima (BUT, if you just LAUNCH yourself, like in catapult, thats another story :3)