If you don't want to get stuck in a long, long line, walk as fast as you can to immigration. It's a slow process and if you are behind a hundred other people you will be there a long time. If you don't have a visa in advance, make sure you fill out the form on the plane and have a new $50 bill ready. They don't accept old money. Make sure it's a new one with the red ink (or 2 20's and a 10) .