I have had an interesting chat about methods for preserving your digital pictures (movies) while being out on an important and long trip. In other words, how to make sure you precious shots come back home with you.
Assumption: you have a way to read memory cards through a computer (not necessarily yours) or use a stand-alone card copier.
Memory cards are pretty cheap. So, why not bringing along an additional extra set, making a copy of a full card and sending it to your home address? You may even prepare addressed envelopes with a thin cardboard reinforce inside. Stamp can be bought as if you were shopping for postcards and you don’t even need a trip to a post office unless you want a Registered letter. Better to send one card per envelope. Once you have safely backed up your picutres (at home), extra cards can be reused for the following adventure.
If you know a trustworthy local, leave her/him your backup copies, either an external HDD or extra memory cards. This will minimize the risk of loss/damage on the journey back home too. If nothing bad happens to your "originals", she/he will keep the hardware afterwards as a reward for the service offered.
Online storage populated overnight is another option, if your hotel has a fast and cheap Internet connection. (If you carry your own laptop consider using Dropbox through my referral link.) But if you shoot a lot (and in RAW ), it might not be practical.
Worried about someone stealing your shots? Either the postman or your local contact person? Encrypt the backup card content with a tool like TrueCrypt. Format the card/disk to resume full, unencrypted, functionality.