Note: You do need an ice cream maker for this recipe. I use THIS ONE.
In a medium saucepan, combine sugar, water and corn syrup. Stir over medium heat until mixture comes to a boil. Without stirring, simmer over low heat 5 minutes. Stir in lemon juice; cool to room temperature. Cut melon from rind, reserving only red fruit. Remove and discard seeds. Cut fruit into 1-inch cubes, making about 8 cups. Puree melon cubes about 2 cups at a time in blender or food processor fitted with metal blade. Stir into cooled syrup. Pour into ice cream canister. Freeze in ice cream maker according to manufacturers directions
photo from BigOven.com