PCWorld: GoodSync2Go Pro: A Simple Way To Synch 2 PCs
You synch files to a USB flash drive then put the drive in the other PC and reverse the process. But this reviewer points out that Sugar Sync, an online service, does the same thing for free.
“If you’ve got more than one PC, you know how frustrating it can be to try and keep their folders synchronized. It’s easy to overwrite new files with older ones, work on older files accidentally, or forget to transfer files from one PC to another. GoodSync2Go Pro solves the problem by using a USB drive to keep them in synch.
You install GoodSync2Go Pro on a USB flash drive, and using it, synchronize files from your initial PC to the USB drive. Then plug the flash drive into your second PC, run GoodSync2Go Pro, and synchronize the files with that PC. You keep using GoodSync2Go as a go-between as a way to keep the folders in synch.”