1. Heat large saucepan of water to boiling. Add vermicelli and cook until just tender, 1 to 2 minutes. Rinse under cold water; drain well.
2. Toss vermicelli with sprouts, carrots, cilantro, and mint leaves until combined. Dip 1 rice-paper wrapper in bowl of hot water just until softened, 10 to 20 seconds. (Keep remaining wrappers covered.) Shake off excess water and place on clean kitchen towel. Place one piece of lettuce on center of wrapper and top with 1/4 cup of the vermicelli mixture. Fold bottom third of wrapper tightly over filling; fold in sides to form envelope. Place 2 shrimp halves, pink sides down, on flap of envelope and roll up tightly. Transfer to serving plate and cover with a clean, damp towel. Repeat with remaining wrappers, lettuce, vermicelli mixture, and shrimp.Make Dipping Sauce::
3. Combine water and sugar in small saucepan and bring to boil, stirring, until sugar is dissolved. Remove from heat and stir in remaining ingredients. Makes 3/4 cup.
4. Serve spring rolls with Dipping Sauce. Makes 2 dozen.