Peel shrimp; devein, if desired.
Stir together hoisin sauce, vinegar, 1 teaspoon sugar, and salt.
Heat oil in a large skillet or wok over high heat 2 minutes. Add shrimp, and stir-fry 2 minutes. Add remaining 1 teaspoon sugar, and stir-fry 30 seconds. Add green onions and ginger, and stir-fry 2 minutes. Add hoisin sauce mixture, and stir-fry 2 minutes. Serve over rice.