Magic - What lies behind

As you mentioned levitation , I will just deal with this as magic is too wide a subject. (Please read below about levitation in general). Google has video links so that you can see the "magic".  Enclosed are 4 links to different levitations.

First explanation: Balducci levitation

The magician positions himself at an angle to his audience from a distance as little as 2 feet as much as 6 feet away from his audience. Making sure to keep the audience small (under 5 spectators) and keeping them grouped close together, the magician puts his feet together at an angle to his audience and stands on the tiptoes of his feet and completely lifts the near foot off the ground making sure to keep his ankles together. Google video has a demonstration of the Balducci levitation available.

http://en.wikipedia.org/wiki/Balducci_levitation

The reverse Balducci illusion is similar to the Balducci illusion, but the magician faces towards the audience at a 90-degree angle rather than facing away. The magician slowly stands on the heel of his far foot as he lifts his near foot up. To improve the appearance of the effect, the magician will try to maintain the near foot parallel to the ground.

Second example:  Elevator Levitation

The Elevator Levitation uses a gimmick that the magician uses to lower himself in the air, it is much better than the Balducci levitation as published in Pallbearer's Review as it can be seen from better angles. Using the gimmick and setting it in position require plenty of practice.

The gimmick that the performer uses to create the illusion, is initially attached to the performer. When the performer is ready to perform the illusion, he sets the gimmick and then rises into the air.

Another variation suggested in The Chronicles in the late 1970s , is called "Elevator 2". In this version, the gimmick is much stronger, and can be carried in pockets more easily. The gimmick can be hidden and carried all day without the performer realising it is there. The Elevator 2 allows spectators to look under the feet of the magician while he levitates. The rest of the effect is virtually the same.

http://en.wikipedia.org/wiki/Elevator_levitation

See also : http://en.wikipedia.org/wiki/King_levitation 

http://en.wikipedia.org/wiki/Sooperman  

The magician "puts his assistant into a trance" and then floats her up and into the air, passing a ring around her body as proof that there are 'no wires' supporting her. A close-up artist wads up your dollar bill and then floats it in the air. A playing card hovers over a deck of cards. A penny on an open palm rises onto its edge on command. A scarf dances in a sealed bottle. Levitations are illusions where the conjurer magically raises something -- possibly including the magician (such as Criss Angel)-- into the air. There are many ways to create the illusion of levitation with names such as the Balducci, the King Rising,and the zero gravity or the eight Gravity.

http://en.wikipedia.org/wiki/Magic_%28illusion%29#Levitation

I have also seen this trick done with a special kind of manual forklift behind a curtain and trick rings.

All the do is place black surface against a black curtain and raise it with the forklift, they then pass trick rings and scarves around it to say there is nothing there, the "audience member" is a pant.