I used to carry a laptop for transferring my photos when travelling for a few weeks. I think it's quite heavy and taxing to do that.
Is there any device to be able to transfer photos and store them without a computer?
Search for 'photo storage' here, lots of links. But these devices are basically a small HDD with interfaces and display - running on batteries. They don't last very long and finally they are shock-sensitive like all hard disks. The right knock and all your data are gone.
Looking at the prices for memory cards I'd rather use more of them and getting a kind of pouch or bag for safe storage. Memory cards even survive drop into sea water.
I opt for more memory cards. But that's coz I don't shoot RAW and I don't have video. I think 8GB is pretty sufficient. At most, I'll bring one or two more 8GB cards, confirm more than enough. You don't even have to buy them! Just borrow from friends! Plus, assuming you've got access to electricity, you can review some of your images when you're back in the hotel room at night and delete those that really cannot make it, really no chance to save ones. That'll free up some space on your memory cards too!
if really in a fix..... find a local internet cafe or photo lab, sort your images into folders of appropriate sizes and burn into CD(s) until you can get home and transfer the images to a safer storage media
Just a couple of years back when the biggest memory card available then was only 1g.... I had to do this when overseas