In a small saucepan, stir together the sugar, water and corn syrup. Bring to a boil and cook to 240 degrees F (116 degrees C) or until a the mixture makes a wispy thread when dripped from a spoon. Remove from the heat and stir in the gelatin. Set aside for just a second while you start the egg whites. If it starts to look weird, give it a quick stir. The gelatin mixture may look grainy, but it will smooth out once it gets mixed in.
Whip egg whites in a clean dry bowl to soft peaks. If you have a stand mixer, use it, otherwise you may need a helper to whip while you pour. Slowly pour, or spoon the sugar mixture into the egg whites while continuing to whip to stiff glossy peaks. Use to frost a cake or cupcakes. This frosting does not need to be refrigerated.