I should come over here more often...
I have helped program some beta uses for those little transceivers or "smart chips" that come in the new credit cards from financial institutions.
cough...AMEX...cough
I can tell you that in the near (not as near as they had hoped) future, just about everything you do will be remotely sensed like the "badge" idea mentioned earlier in this thread.
It's not visual it's RF. They already use a weekly developed version of this at "Mobil" gas stations and a couple of other odd places.
All you will have to do is get within a pre-determined distance of a matching transceiver and the code will run for that locations particular purpose (i.e. take your picture, charge your credit card or whatever the code has it do). The "smart chips" will have security features so no one without the right security level can get too much information (same as SSL tech.) If the resorts provide these to guests instead of say...keys (I doubt it, they are still pretty expensive) they can make the resort TV systems addressable and you just need to switch to that channel and view just YOUR pictures or whatever. Each room's channel "99" or whatever would be different. This would also allow the servers to compare your chip with those chips around you and determine if it needs to be sent to more than one room or not.
I'm not sure why anyone thinks there would be a stumbling block of taking the picture with the ghost. It seems pretty simple to do with basic "buggy" id's and a fairly simple a==b matching script for whatever ghost you appeared with. IR lights are plenty bright enough for the right CCD.
I would think they would take multiple images for each party and let you pick out the one that your eyes are actually open in.
Ok, I think I've lectured long enough. Back to the basement for me