Your complaints about digital cameras in terms of reaction time were true many years ago. Since the introduction of the Nikon D-series and the Canon digital SLR line (D30, D60, 10D, 1D, 1Ds, Digital Rebel) they are no longer true. (Earlier, Kodak and probably other manufacturers had fast digital SLRs but they were in the $10K-$20K realm.)

Most cities your friend visits will have tech shops that will download his pics and burn a CD for him. Check out Lonely Planet's Thorn Tree for lists of shops and to post requests for shop locations on your route. The most popular solution is to burn two disks: mail one and carry the other.

He could also bring his software and connection cable to any similar shop and upload your pics to a service like O-Photo for net storage and sharing with your friends while on route.

These solutions are not flashy but they are cheaper and simpler than most that have been suggested.