Shrimp Tostadas with Corn Salsa

Name: Shrimp Tostadas with Corn Salsa
Ingredients: 3 tomatoes, seeded and diced finely*; 2 ears corn, kernels removed; 1/2 white onion, chopped finely; 1 jalapeño, minced; 1 large avocado, diced finely; Juice of 1 lime; 1/4 cup cilantro leaves; 1/2 teaspoon salt; Vegetable oil, for frying; 6 corn tortillas; 1 1/2 cup flour; 1 pound extra-large (26-30 per pound) peeled and deveined shrimp, rinsed and tails removed; 1 teaspoon salt; 1/4 teaspoon cayenne; 1 head iceberg lettuce, shredded; 6 sprigs cilantro, for garnish; 1 lime, cut into 6 wedges, for garnish