Remove any clams that are broken, or which do not close immediately if tapped. (I prefer smaller clams if you can find them, but not the tiny ones.) Place in a large skillet and cover. Cook for about 5 minutes or until the shells open (discarding any clam with a shell that does not open).
In another large skillet, heat olive oil and sauté the garlic until golden. Add the tomatoes and allow to simmer for about 10 minutes. Add salt and pepper.
Remove the clams from the skillet with a slotted spoon and then remove most of them from their shells. Place the clams into the skillet with the tomatoes. Add some of the remaining liquid from the clams.
Meanwhile, bring a large pot of salted water to a boil. Cook the spaghetti until al dente (2 minutes less than package recommends). Drain the pasta and add it to the skillet with the clams. Mix in the parsley. Serve immediately, evenly distributing the clams. Sprinkle with crushed red pepper for a little kick.