Piet Hein Drink Cooler
It's a stone, it's an egg, it's... actually a sort of metal ice cube designed to chill your drinks without the diluting effect that ice has. The Piet Hein Drink Cooler is made of seamless stainless steel and has a liquid core, which hardens when the egg is frozen and allows the cooler to actually cool your drink. They are no larger than ordinary ice cubes, so the only potential downside is that you might have to pay a bit more attention to what you're doing when you toss ice into glasses. Price: $31 each.