Stir together the curry powder, oil, lemon zest, and cilantro and toss the shrimp in the marinade to coat. Refrigerate, covered, for at least 6 hours and up to 12 hours or overnight.

Spray the grilling grate of a gas or charcoal grill with vegetable oil spray. Preheat the grill to medium hot.

Lift the shrimp from the marinade and arrange on a clean plate. Squeeze the lemon over the shrimp. Thread the shrimp on four metal skewers, six shrimp on each skewer with a little space between each one. Season with salt and pepper.

Grill the shrimp for 2 to 3 minutes on each side until cooked through. Serve with pineapple salsa.