1. Fill a shallow dish with warm water. Dip each spring-roll wrapper in water; place between damp paper towels for 10 minutes. In a large bowl, combine lettuce, shrimp, carrot, scallion, cilantro, 2 tablespoons peanut sauce, and 1 tablespoon rice vinegar. Toss.
2. In a small bowl, stir together the remaining 3 tablespoons peanut sauce and 1 tablespoon rice vinegar; set aside. Place 1/2 cup of the shrimp mixture half an inch from the bottom edge of a wrapper. Fold bottom edge of the wrapper over the filling. Fold sides over and roll up. Repeat with remaining filling and wrappers. Cut each in half; serve with dipping sauce.