Serve corn on the cob already buttered so guests can dig right in. Bring water to a boil in a stockpot (don't add any salt; it toughens kernels), and drop in 6 to 8 ears. Return to a boil, then cook two to four minutes for crisp-tender corn. When ears are just about done, slice eight tablespoons of unsalted butter, and drop them into the cooking water; stir to melt. The butter will float, and each ear will get an even coating as you remove it from the pot with tongs.