I'm on the road since more than a year in a round-the-world trip and I think my setup is fit.

Two notes,
- when travelling, internet connection level changes a lot and sometimes you can be not connected for days, so an external disk/memory card rotation should stay your primary backup, especially for photos
- for pictures, I'm taking both JPG+RAW and doing Internet backup only for JPG. If I have a full internet connection at my accomodation and can let transfer during night, if not day, it's working pretty well. RAW (10M per file or more, 5-10 times the JPG) is clearly not possible.

For small files (txt, id/passport copy, ...), using Dropbox as primary (want to stay free), and lsyncd with my home server
For pictures, nothing more powerful than rsync (at least, in one-way; if you make change at both place, could be interesting to check unisson) to my home server or NAS.
rsync is particularly good, as for now, my main changes on pictures are metadata and from what I tested, both lftp and Dropbox would transfer all the files if there is a minor change.

CD/DVD are way too small for JPG+RAW. maybe JPG only.
Of course, no pictures transfer if connection is poor or limited (3G or filtered). For China, need to pay for a VPN provider ...

one interesting thing would be to run some virtualization on ppc/macosx

i know about mac-on-linux. but what about any xen/user-mode-linux or else natively on macosx ?

best of all world, many systems, one hardware, no reboot between them ...