Place pork cubes in resealable plastic food bag. Add limeade, rum, chopped onion, parsley, salt and pepper; mix well. Marinate in refrigerator for 3 to 4 hours.
Heat charcoal or gas grill to medium. Coat both sides of lime slices in sugar; set aside.
Arrange pork cubes, onion wedges and lime slices on 6 skewers. Cook kabobs on grill, turning occasionally, until pork is done.