2 cups frozen strawberries
2 cups ice
4 oz. light rum
3 tbsps. sugar
1 lime, juiced
Dump the ingredients into a blender, ice first, and blend away. The setting you use depends on the blender, so experiment. Depending on the blender, you may need to help get the strawberries down to the blade. Just don't do so with a wooden spoon while the blade is spinning or you'll end up spending half an hour picking out splinters.
Makes 2.
Future research: try putting the frozen strawberries in before the ice; try water instead of ice; try a dark rum float.