Hurry up and wait. Often the M.O. in Nicaragua, but it was a huge part of our trip to the States too. Because we had such a large group (19 kids, 3 adults) and traffic could be such an unknown factor (especially in Chicago), lots of space was given for the potential to be late and preparation time so there was always a fair amount of waiting.
Sometimes entertainment was provided, sometimes it was self-constructed. One church had a playstation video game player which transfixed the kids. One of the men from the church seemed surprised when I explained that the kids didn't have video games at the orphanage, but he seemed even more stupefied when I told him that it was a good thing.
Jayden, one of the chaperons who lives on the island with the kids was always good for distraction and if nothing else, the kids would always find something to hold their attention (sometimes good, sometimes bad!).