Generally, do security a courtesy by being early for your flight. If you are there with time to spare and there is not a huge line, they will be much more willing to do a hand check. Don't hand them 100 rolls and expect a hand check. If you are traveling to a major city and have done your homework, you are probably better off bringing a few rolls with you and then buying the film at your destination. It may cost a bit more, but it is worth it if you are going to be going through multiple x-rays. This goes double or triple if you are shooting high ISO's. It is going to be better to buy Delta 3200 or TMZ at your destination than it would be to bring it with you. ISO 100 film will hold up a lot better. If you cannot buy your film at your destination, it will help to develop it there, or if not, then just smile and try to get a hand check. It always helps if you speak the language. People say they could never get a hand check in Japan or Russia, but I never have had a problem since I speak the languages. Politeness and a basic command of their language goes a long way.