Starting right about now, I make sure to always have the bowl of my ice cream maker in the freezer, so it's always frozen and ready for action. In addition to making ice cream, it also works as a great impromptu ice bucket for chilling beverages.
Photo by Claire Lower.
Just pull the bowl out, fill with water, and place your bottle of champagne, beer, soda or whatever down in there to get nice and frosty. When you're done, just dump the water and pop the bowl back in the freezer. It chills pretty quickly, and you don't have to worry about making or buying ice. (Obviously I'm not telling you to go run out and buy an ice cream maker just for this purpose, but it's a good use for a seemingly single-function item.)