This recipe is from the Cooking Light Magazine.  This is the "easier" version.

1 lb medium cooked shrimp
1/2 c coarsely chopped fresh cilantro
1/4 c fresh lime juice
1 T minced seeded jalapeño pepper
24 (6-inch)white corn tortillas
3/4 c chopped tomato
1/2 c light sour cream
1/2 c chopped green onions
2 limes, quartered

-Heat up shrimp in a skillet with some salt and pepper, just until heated through, do not over cook since they're already cooked.
-Add to shrimp the cilantro, lime juice, and jalapeño pepper, tossing well to coat.
-Heat tortillas in large ziploc bag in microwave. Double up tortillas-one always breaks and makes a mess-so in your 2 tortillas spoon a little of the shrimp mixture; top with 1 tablespoon tomato, 2 teaspoons sour cream, and 2 teaspoons onions.

-Makes 10-12 tacos.