We always tip the porters wherever we are. Going in, usually $5 for 2-3 bags. In FLL, we just raise our hand when we get into the luggage claim area and they come right over with their cart and pick up all of our bags, even the carry on that we have with us. Last trip, the porter took us through immigration and outside to the area where our car shuttle van was located, a trip I don't think I could have done without him. Tipped him $10 and well worth it. I figure I've just spent thousands on a vacation and they deserve a decent tip.