Hey, thanks for the hours of entertainment. I enjoyed the letters as much as the photos. I found this moth on the stairway of my condo in Palm Springs on 9/13/07 and was startled by his size. I looked at every moth photo you have, in 9 different menus, until I found the manduca sexta (tobacco sphinx) in the moth sphinx index. I also visited the Butterflies and Moths of N. A. site as you suggested and this guy could also be the occult sphinx, or the five spotted hawkmoth. Since you seem to have only one or two photos of them (and a hundred black witches) I thought you could use another. The wing span as pictured here is about 3 inches across. Thanks for re-awakening my sense of wonder.
You are correct. This is Manduca sexta, commonly called the Carolina Sphinx and, because of the caterpillar, Tobacco Hornworm.