In 4-quart saucepan, heat 8 cups water to boiling over high heat, add shrimp and heat to boiling. Cook 1 to 2 minutes, or until shrimp turn opaque throughout. Drain well. Place shrimp and olives in 13" by 9" glass baking dish.
In 1-quart saucepan, heat oil over medium heat, add curry powder ginger, salt, and pepper and cook, stirring constantly, 1 minute. Remove saucepan from heat, stir in lemon juice and parsley. Pour warm marinade over shrimp and olives in baking dish.
Cover and refrigerate at least 2 hours, until well chilled, tossing occasionally. Place shrimp and olives on platter, garnish with lemon slices and celery leaf. Serve with cocktail picks.