On Britain's Got Talent, an illusionist sat on stage while a sheet was pulled over a chair, making him instantly disappear and reappear in a different spot.  When asked how he did it, he offered to make an exception and explain.  He put on a reflective white jumpsuit and turned on UV lights to show the audience the secret escape route on the back of the chair.  Then came the real twist.  Even with the white suit glowing, the lights fully up, and everyone watching every move, he stepped back into the chair, dropped the sheet, and vanished into thin air again in a split second!