There are several issues involved with traveling with a digital camera, mostly concerning image storage and batteries.
Regarding image storage, my Golden Rule is:
ALWAYS HAVE YOUR IMAGES IN AT LEAST TWO PLACES!
Copy them from the card at least daily
DO NOT delete them off of the memory card until they are in TWO of the following places:
Other media card considerations:
I recommend using multiple lower capacity cards than one great big card because I’ve seen cards go bad, and there’s also the issue of cards getting lost or stolen (less of a problem if you follow Golden Rule above!).
Remember that, unlike film, there is no problem with digital camera cards going through x-ray.
Regarding batteries – I strongly recommend having a backup battery or set of batteries, and always carrying a charged backup with you. There’s nothing worse than running out of battery just as the best shot of the day appears.
Likewise, carry your charger with you to pop into the outlet at the restaurant while you eat lunch. Remember to put your camera on the table in front of you with the battery cover OPEN to remind you to retrieve it before you leave!
One more thing – tape your name and contact information (at least your email address) onto your camera and anything else of value to you. Hopefully, if you lose it, you’ll get lucky and an honest person finds it and reaches you.
Have a great trip!