Amy, do you have a Whole Foods market in your area? Or if not, check your phone book for a middle eastern market. You'll find tahini there. Making the hummus really is easy and you'll be sure you aren't getting any nasties like HFCS in it
I sometimes throw in sesame seeds if I don't have tahini. As someone has already said, peanut butter works too. To make the red pepper hummus, I add my pureed roasted red peppers from the freezer. Would you believe I bought a case (28 pounds) in the fall, roasted and pureed them? Martha has nothing on me!