Not Your Average Mug

Think Geek/Arcade Mugs

You pick from two options: (Pac-Man or Space Intruders). This mug, when cold, will display an empty maze or starry sky.  Just add hot water to watch the mugs populate and come alive. It's only $7.99 and you can purchase one here:  ThinkGeek

Product Features

• Nifty Mugs change their design when you add hot coffee
• Choose from Pac Boy or Space Intruders designs
• Standard Mug Size - 3.75" high x 3" in diameter
• Hand-wash only: If you put this mug in the dishwasher, the color changing effect will melt in the extreme heat. Love it like a child (unless you put your children in the dishwasher, that is).