Oh, how I love this. Recipe courtesy of www.allrecipes.com. I used cucumber instead of celery, and I left the avocado separate so it didn't brown and added with each serving. Serving size is estimated.
Place shrimp in a glass bowl and cover with lime juice to marinate or cook for about 10 minutes or until they turn pink and opaque.
Meanwhile, place the plum tomatoes, onion, jalapenos, avocado, and celery in a non-reactive stainless steel glass or plastic bowl.
Remove shrimp from lime juice, reserving juice. Dice shrimp and add to the bowl of vegetables. Pour in the remaining lime juice marinade. Add cilantro and salt and pepper to taste. Toss gently to coat.