2/3 cup sugar
1/2 cup water
3 cups 1-inch pieces peeled seeded cantaloupe (about 1/2 cantaloupe)
Combine sugar and water in medium saucepan. Stir over medium heat until sugar dissolves. Bring to boil. Transfer to 11x7x2-inch glass dish and chill until cold, about 2 hours.
Puree cantaloupe in blender until smooth. Add to sugar syrup in dish and stir until well blended. Freeze until almost firm, stirring occasionally, at least 3 hours or overnight.
Transfer cantaloupe mixture to large bowl. Using electric mixer, beat until fluffy. Return to freezer and freeze until firm (do not stir), at least 3 hours or overnight. (Sorbet can be prepared 3 days ahead.) Cover and keep frozen.