It's true there isn't really an allergy free cat, but some people certainly have less of a reaction (or no reaction) to certain breeds. Technically, "hypo" means "less" anyway, so hypoallergenic in its true sense means something that causes fewer allergies. I'm horribly allergic to most domestic cats, but we got a bengal cat and I haven't had any issues with her at all. I was (pleasantly) surprised. Here is another article about hypoallergenic cat breeds:
http://www.infobarrel.com/Breeds_of_Hypoallergenic_Cats