What is a good ceviche shrimp recipe?

Simply Recipes (http://www.simplyrecipes.com/recipes/shrimp_ceviche/) and Food Network (http://www.foodnetwork.com/recipes/saras-secrets/shrimp-ceviche-recipe/index.html) have some Excellent shrimp ceviche recipes. They suggest that you pre-boil your shrimp to destroy bacteria and use 4 lemons/limes per pound of shrimp.