Airport Security
Don't place single-use cameras or unprocessed film in any luggage or baggage that will be checked. This includes cameras that still have film in them.
If an attendant or security personnel informs you that your carry-on baggage must be stowed with the checked luggage or go through a second scan, you should remove your unprocessed film.
If you're asked to step aside for a more thorough search of your carry-on baggage, you should be advised that film could be harmed and you should take it out of your luggage.
Keep your film in a small bag of its own - preferably a lead-lined bag or, failing that, a clear plastic bag. You should also remove all the packaging material from your film (both box and plastic canister). These steps make it much easier to remove film from your bag and also facilitates any hand-checking of it by security.
Ask to have your film checked by hand - in the U.S., FAA and TSA regulations allow you to do this. Be aware that not all airport security officers are aware of this regulation, though. If you have trouble, ask to see a supervisor. However, even if they insist on x-raying the film, don't panic - only the highest speed films will have fogging from this scan.
The effects of x-rays are cumulative, so if you expect to pass through multiple x-ray security checkpoints (4 or more), it is more important to seek hand checking.
Consider shipping your film. We understand that express air package shipping services such as UPS, DHL, FedEx, etc. do not employ x-ray scanning of customers' packages on domestic routes. However, this should be verified when sending film. The same carriers may employ passenger airlines for international routes. Goods shipped as freight on passenger airlines are subject to high-intensity x-ray scanning. It is recommended that film shipped as unaccompanied freight is labeled:
"DO NOT X-RAY. IF X-RAY IS MANDATORY, DO NOT SHIP / DO NOT X-RAY / CONTACT SENDER URGENTLY: (details)".
If you plan to travel through international airports sometimes use stronger scanners or refuse to hand-check film. In time, security measures at airports may increase, and stronger scanners may be used to scan even carry-on baggage. Be aware of the signs in the airport. Most carry-on baggage scanners, at this time, will be marked as "Film Safe" so they will not damage your film.
Be polite, helpful and patient. Please remember that security personnel are trying to protect the traveling public.

General Tips
Take more film than you think you'll need with you. Film in tourist destinations is often very expensive. Also, try to take more pictures than your first instinct - remember, you may not return to that destination for some time.
If traveling by car, avoid leaving your film in the car for long periods of time with extreme heat or cold, both of which can severely damage film.
Many museums and similar tourist destinations are starting to employ airport-like security. Keep the above guidelines in mind for these destinations as well.
Keep a few plastic film canisters on hand in case of rain or other wet conditions.