1. Place coconut in a small skillet over medium heat. Cook, stirring frequently, until coconut is golden and lightly toasted. Transfer to a bowl.
2. Preheat grill to medium. In a small bowl, combine lime juice and sugar.
3. Oil grill. Put pineapple wedges on grill and cook, turning once, until softened and browned in spots, 7 to 8 minutes total. Transfer pineapple to a dish and dot with lime juice mixture.
4. Just before serving, arrange pineapple on a platter and sprinkle with lime zest and toasted coconut.