Made by Thinkgeek:

Product Features

• Silicone ice cube tray creates frozen water in the shape of the Pi symbol
• Perfect for simultaneously conveying your knowledge of mixed drinks and math
• Great for casting other materials, such as meat loaf, in the shape of the Pi symbol
• Damn Impressive to Archimedes
• Tray makes 12 Pi Ice cubes at once
• Each cube is approximately 2.24" x 1.75" x 0.5" deep