Another way I love to use pesto (recipe here) is with some spaghetti and sausage!
I start with about a 1/4 cup of pesto, and add about 1 1/2 cups of pasta water in a large saute pan. Mix the pesto and the water together well, and cook the sliced sausage in the watered down pesto mixture. Pesto on its own is a little too strong to use as a pasta sauce, but when I combine it with a little pasta water, it makes a great sauce! Serve over spaghetti and top with a little additional grated Parmesan cheese. 🙂