HI Rob,
I had been wondering why you did not book a phantom while onboard the Grand. Just make a mental note next time as it is a very small investment with some great benefits.
Our cruise that we booked two weeks ago must be booked within the next two years (by 2005) You can either assign a TA to it right then and there as we did (Lori received a copy already of our booking by fax from Princess) or you can leave it open, find a TA later and then fax a letter to Princess assigning it to a specific TA.
As for the modify/upgrade question, I am not sure what you are talking about on that one so I am going to guess a bit. When you book a phantom onboard, you do not choose your category or sailing, all of that can be done at a later date. All this booking is, is a deposit on a future cruise. You choose the cruise, cabin category and such later on. So you aren't commited to just one type of cabin or anything like that. You are free to book whatever you like at a later date. That is why we always book phantoms instead of trying to decide while onboard which cruise we want to take later on.
Hope this answers your questions.
These bookings are a great way to make a very small deposit on a cruise and also get extra cruise credits (which can be added to anything your TA might offer as far as onboard credits for that sailing). It ties up so much less money than doing it the regular way. I know that last year, our deposit on a back to back was going to be $1600 but since we used two phantom bookings it was only $400, which we had already paid on our last cruise.. So we did not tie up so many funds for a long period of time.