OK, from experience:
HDD option is a good option but it is storing all your eggs in one basket. Always back up your important shots elsewhere (eg online storage, or leave a copy on memory cards)
Internet Cafes in SE Asia - Most allow anyone to plug any device in (hence all the viruses). Some do not allow it at all. A few will allow it ONLY after they have virus scanned your device (which can take hours for a full large drive, though they're unlikely to charge you for this time).
Viruses - I find there's a lot of scaremongering about viruses. As far as I'm aware there isn't one that will wipe all the images off your drive. I picked up a lot on my portable HDD travelling around China - I probably helped spread them, unknowingly. But when I got home and plugged it into my PC my virusscanner cleaned them off, no harm done.
http://imaging.carbonmade.com