1. Fill a large plastic/paper cup partially with water. Put a small cup with water inside the large one. Press down until both cups are flush at the same level, adjust the water level accordingly. Place a strip of duct tape accross the top of the two cups to hold the small one in place and freeze.
2. After the contents are frozen, remove the small cup from the large cup. Cups with a waxy finish should pull right out with very little effort.
3. Run the cup under very warm water (not too hot or it might crack)
4. Remove your new ice shot glass from the cup
6. Gatorade make for some pretty cool shot glasses as well.