Preheat the oven to 350 degrees F (175 degrees C).
Spread the spaghetti sauce in an even layer in the bottom of an 8 or 9 inch square baking dish. In a medium bowl, mix together the crabmeat, cream cheese, and Cheddar cheese. Season with Old Bay, Worcestershire sauce, pepper, and salt. Spoon over the spaghetti sauce layer, and spread evenly.
Bake for 40 minutes in the preheated oven, or until the top is golden brown. Serve immediately with thinly sliced baguettes or crackers.