Spoon bending
There are several methods of creating an illusion of a spoon spontaneously bending, without any apparent force applied to it by the illusionist.
The most famous spoon-bender is the Israeli-born Uri Geller, an alleged psychic who claims to be able to bend spoons, as well as other metal objects. He has numerous critics, though, especially in the scientific community, who claim he is both charlatan and con-man (see James Randi).
One example of spoon-bending in popular culture is the "There is no spoon" scene in the 1999 film The Matrix, where a boy says: "Do not try and bend the spoon. That's impossible. Instead, only try to realize the truth . . . There is no spoon . . . Then you will see that it is not the spoon that bends, it is only yourself."
Explanations
Most common is the practice of misdirection, an underlying principle of many stage magic tricks. In one or several brief moments of distraction, a "psychic" or magician can physically bend a spoon unseen by the audience, then reveals the bend and thus creates the illusion that the spoon is bending before the viewers' eyes. The spoons usually bend at the point where the bowl meets the handle, where bending requires the least force.
Another common tactic is to repeatedly bend a metal spoon at the neck (in preparation for a performance), almost to its breaking point (some practice is required to perfect this "talent"), so that simply flicking it slightly will cause it to bend conveniently in front of an awe-inspired audience. Skilled magicians are often known for their abilities to make otherwise sharp and obvious flicking actions appear quite smooth and natural, which certainly enhances the realism of this illusion.