Three day hopper passes are often available through many independent ticket wholesalers like Ticketmania, Paramount, Florida Orlando Tickets, etc. But you have to call them to find out if they have them in stock as they are not allowed to advertise them on their websites.
Two day hoppers are special convention tickets that you must be part of the convention to get. There are some exceptions such as large groups like the recent Gay Days event where convention-type tickets were available to the the general public who would be attending that event. You could order them online even if you weren't going to be attending the event. But that is the exception rather than the rule.
