David Pescovitz: Here's a massive list "1001 things to do with liquid nitrogen." Two examples: Freeze a can of shaving cream and then peel the can away from the cream. Put the canless cream into someone's car. Let the oven-like heat from the car's sitting in the sun defrost the shaving cream. 2 cans will fill an entire car. (Coulter C. Henry, Jr.)... Try taking a ping-pong ball and poking a small hole in it. The hole has to be tangent to the sphere of the ball. When poking the hole use a pin and the pin should be almost flat agianst the ball. Basiclly you want a hole in the side of the ball that will cause the ball to spin. Submerge this ball into the liquid nitrogen and let it fill up. Place the ball on a table and watch it spin. As the nitrogen goes back to a gas it will rush out the hole and presto!! It's pretty cool. If it does not spin try placing your hand on it to warm it to get it started. Link