Mix together the crab, chilli, coriander, mint, lime rind and juice and the ginger in a bowl.
Spoon equal amounts of the mixture onto the lettuce leaves. Roll them up and set them aside.
Make the dipping sauce. In a small bowl mix together the sugar, vinegar, lime juice and soy sauce until the sugar has dissolved. Stir in the chilli and spring onion.
Serve the crab lettuce rolls with the chilli sauce for dipping in a separate dish.