Preheat a grill to medium high and brush the grates with vegetable oil. Toss the scallops with the olive oil and curry powder in a large bowl; season with salt and pepper. Thread the scallops, cherry tomatoes and squash onto eight 10-inch skewers.
Combine the melted butter and ginger in a small bowl. Grill the kebabs, covered, turning once, until marked and cooked through, 5 to 7 minutes. Remove from the grill and brush with the ginger butter. Sprinkle with the cilantro and serve with lime wedges.