If we were on a once-in-a-lifetime trip we would take a portable back-up storage device, probably a seven-inch Android tablet with a USB connector and a microSD expansion slot. The Samsung Galaxy Tab 7.7 fits the bill, and its wi-fi will connect you with the cloud. Dropbox, Microsoft SkyDrive and Apple's iCloud provide secure back-up.
Adding together the memory in the tablet, the microSD card and the cloud means there is no need to perilously overload the memory card. (Check that you have a camera-to-tablet connector cable; it may be an option to be purchased.)
Android tablets are better than Apple iOS devices for this process because when you get home you can connect them to your PC and transfer the photo files without having the torment of iTunes.
Finally, the best security procedure is to unload the memory card every night so it never becomes too full.
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