A friend made this for a baby shower I hosted recently. It was delicious.
1/2 cup sugar
3 tablespoons sweetened condensed milk (I never really measure this. I just taste it)
3 cups of cold water
Wash limes thoroughly. I wash mine in a little dish soapy water to get all the wax and bacteria off. Cut off the hard ends and slice each lime in to 4-8 wedges (it depends how much you trust your blender). Place limes in a blender with the sugar and water, pulse 5 or so times. Strain through a fine mesh strainer or remove rinds. Then add sweetened condensed milk to taste. Serve over lots of ice.