The Anti-Gravity Cigarette.
A cigarette is laid on the table so that about two-thirds of it protrudes over the edge. Yet the cigarette does not fall.
There are two methods of performing this trick. The first requires a prepared cigarette. A bit of metal is hidden in one end of the cigarette, and as that end is much heavier than the other, the cigarette can easily be set so that it apparently overbalances the table edge.