Hate having to scrape the jar in order to remove as much of the pasta sauce as possible? If so, try this simply, yet handy trick, courtesy of K.
Place the jar of pasta sauce, unopened and upside down, under hot running water for 3 to 5 minutes. The sauce will easily empty from the jar, leaving very little behind. This works best for cream or cheese based sauces (i.e. Alfredo), but it also works well for tomato based ones such as marinara.