I saw a very funny, very charming French patissier, a guy who'd won the MOF, on that talk show "A Chef's Life." He did the balloon trick in the cooking part.
He was very funny about it. He started by dipping the balloons in the chocolate three times, to make three-lobed leaf shapes, and then he remarked, "you're supposed to be quite careful how you remove the balloons, so you don't break the chocolate. You untwist the neck and let out air slowly, you see?" And then he stabbed them with pins, laughing. Came out perfect.
He also did this truly cool thing where he first drizzled white chocolate in a little random swirl on top of the dark chocolate, and when he dipped and popped the balloons you got this beautiful contrast pattern.
Jacques something, I think. Name escapes me. Check it out if you have a chance, though.