A simple, impromptu trick using a cigarette and a tube.  The cigarette is clearly pushed into the tube and a cap put on the end.  Without hesitation, the tube is handed to a spectator to open, yet the the tube is empty other than a miniature tiny cigarette, all is left in their hands for full examination.  Instead of the mini cigarette, a match could be used.  Ideal used as a topic of the magician 'giving up smoking'.