USE A SHOULDER BAG OR MESSENGER BAGThere are some really great shoulder & messenger bags out there made specifically for camera gear. This option works especially well if you only plan to travel with one camera/lens and would like something a bit lighter or just more discreet.
Pack your cameras in your carry-on luggageSo if you pack your cameras and lenses in your hold luggage, it's much more likely that you're going to have a few breakages. It's okay to put non-delicate camera accessories in your hold luggage, like memory cards, battery chargers or even some tripods.
For security, you'll need to be able to put it in a bag. They won't want it loose. You certainly can't where it around your neck when you go through security, It might be a different issue for the airlines.
Firearms, ammunition, and fireworks are prohibited, as are all knives and safety razors (including pocket knives and Swiss Army knives). Straight razors and replacement blades for straight razors are also not allowed. Most tools also cannot be packed in carry-on luggage, as they have the potential to cause harm.