A few thoughts on laptops. On my last trip i purchased an IBM T-23 for $500. The battery was shot and it needed a new CD drive. These parts are available on E-Bay for cheap, and with a PayPal acct., you could probably talk the seller into shipping parts to an un-confirmed adress, like i did when i was in Reno.
If you choose to run a PC, i wouldn't settle for anything less than XP. It works, well, most of the time anyway, and accepts current software. Old operating systems will give you trouble when trying to load new software. PC is easily infected with vermin from the internet, use someone elses computer for surfing and use yours strictly for photo's, movies, GPS, etc... If you run it without anti-virus software, it is remarcably fast! When packing, place it on top wrapped in a shirt or you run the risk of breaking the display when running off-road. The IBM is a great choice and parts are cheap and available. Also, if you damage the harddrive, you can send it to any IBM office in the world where they will most likely retrieve your info, something most computer companies donot offer. You can find IBM in almost every major city in the world.
My laptop survived three months of hell, with dead batteries and a broken screen. It was a great computer...unfortunately it was a PC. I've recently gone the Mac route and sold every PC related item in my house with great satisfaction. Its simple, well build and WORKS over and over again...no more blue screen of death! If it survives my next trip...thats yet to be determined.