In a medium bowl combine the salsa ingredients. Cover and refrigerate until ready to serve.
Prepare the grill for direct cooking over high heat (450° to 550°F).
Season the salmon on both sides with the salt and red pepper flakes and then drizzle with the lime juice and oil.
Brush the cooking grates clean. Grill the salmon, flesh side down, over direct high heat, with the lid closed as much as possible, until you can lift the fillets off the grate with tongs without sticking, 6 to 8 minutes. Turn the fillets over and continue cooking to your desired doneness, 2 to 3 minutes for medium rare. Slip a spatula between the skin and the flesh, and transfer the fillets to serving plates. Serve warm with the salsa.