I just finished posting on one of those cruise message boards. Most of the people from my cruise seem to have been posting since January or February. It was interesting reading, but I don't see myself becoming fast friends with any of these people. All of them appear to be couples, mostly all retired, and most of them seem to cruise two or three times a year.
I think the main reason for posting is to cut the costs of the shore excursions, but I am not really sure that I would enjoy any of their side trips.
We shall see.