Combine first 3 ingredients in a small saucepan.
Bring to a boil; cook over medium heat, stirring constantly, until sugar dissolves.
Remove from heat, and let cool slightly.
Position knife blade in food processor bowl; add cantaloupe.
Process until smooth.
Transfer to a large bowl; add sugar mixture and lemon juice, stirring well.
Cover and chill thoroughly.
Pour mixture into freezer can of a 2-quart hand-turned or electric freezer.
Freeze according to manufacturer's instructions.
Let ripen for 1 hour, if desired.
Scoop sorbet into individual dessert bowls.