h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

It goes something like this. You give the person you are performing the trick to a single match stick. (They can provide their own if they happen to have one). Next you hold out a handkerchief and ask them to place the match stick in the middle with which you then wrap the match stick up in the hanky. Keeping a hold of the hanky you let them grasp the match through the cloth and then tell them to snap the match in half. They do this. You then unfold the hanky to reveal the match that they broke which is magically un broken and in one piece.

To do this you need the type of cloth hanky that has a sewn hem all the way around. Into the hem you previously secrete another match stick prior to performing the trick. When you then wrap the match stick from your "victim" up in the hanky, you make sure that the stick they grasp and break is the one securely in the hem. This broken stick then stays in the hem when you un-wrap the hanky revealing the "victims" un-broken match. Provided you do not let them examine the hanky the trick works well.