I found this recipe off of the This Week For Dinner website (there's a link on the side). I haven't tried it yet but I thought that was such a good idea to use ravioli for a quick lasagna.
This is from Real Simple magazine
1 26-ounce jar pasta sauce
1 18-ounce bag frozen large cheese ravioli, unthawed
1 10-ounce box frozen chopped spinach, thawed and squeezed dry
1 8-ounce bag shredded mozzarella
1/2 cup (about 2 ounces) grated Parmesan
Heat oven to 350° F. Spoon 1/3 of the sauce into a 9-by-13-inch baking dish. Place 12 ravioli on top. Cover with the spinach and half the mozzarella. Add another layer of ravioli and the remaining sauce, mozzarella, and the Parmesan. Cover with foil and bake for 25 minutes. Uncover and bake until bubbly, 5 to 10 minutes more.
I'll post a picture when i try it and let you know how it goes!