And don't miss this handy top 10 list: How to tell if your prostitute is an extraterrestrial, which contains the following gem:
10. Squeamish about spanking -- Terrestrial prostitutes are willing to perform virtually every sexual act if the money is right. But ETs don't like having their butts touched.
I should point out that this list is obviously a joke because they left out the most obvious sign that your prostitute is an extraterrestrial:
11. She doesn't charge extra for the anal probe.