In a large skillet, melt butter. Using a wooden spoon, add brown sugar and stir together. Add the bananas and cook until caramelized on both sides, over medium-high heat. Move pan off heat, add the rum and return to the stove to catch a flame from the gas stove or a long lighter. Stand back when ignited and flambe the bananas. Be careful a flame will shoot up above the pan. Let flame die down and the alcohol cook out. Serve bananas over vanilla ice cream and/or a slice of pound cake.