How do I back up my iPhone to my laptop while I'm on the road?

My iPhone is sync'd with my home desktop computer, but I am away from home for 3 weeks.

I did not reconfigure the iPhone to sync with my G4 Powerbook that is also traveling with me.

I didn't have time to move the iTunes library to my laptop, but I figured that I really didn't need to sync my iPhone with the laptop while I was traveling out of the country, BUT... my iPhone froze on me. Fortunately, it rebooted after a hard shutdown. Now I'm worried that it might freeze on me again and need to be restored, but I can't do that while I'm on the road, because my iPhone isn't sync'd with my laptop.

THE QUESTION:

How do I back up my iPhone to my G4 laptop running OS X 10.4.6, so that I can do a restore if necessary? I am currently traveling in China, which may cause some additional problems, as far as accessing software websites to download.

I don't have access to my home mac, so the fixes where I need to access the file with the code in it won't work for me. Any other suggestions?