Try this spicy syrup in a Fiery Mango Margarita (shown). If you're scared of the chile's heat, where latex gloves while slicing.
Stir together sugar, water, and sliced chile in a small saucepan. Bring to a boil over medium-high; cook 1 minute. Remove from heat; let stand 20 minutes. Pour mixture through a wire-mesh strainer into a bowl; discard chile slices. Chill syrup until ready to use.