What are your favorite?
Il go first
You in a bar drinking with some people. Ask some1 to help you with the trick, he will be your victim. Get him to place his thumbs flat on top the table and on the edge about half an inch apart. Distract you audience with a random object e.g. "now look at this box of smokes im holding up". Use this distraction to place your victims pint (with your free hand) on top of his thumbs

He is now reasonably unable to move or he will knock his own drink