I just installed Windows Live Mesh, it syncs the folders/programs I want on the computers I select (PC only) and also makes a back up of that folder(s) file(s) in the cloud providing you select that option.
It's great for me because I have 3 macs that run windows, my Air and 2 iMacs for work so I can take the Air and go wherever and still work while it keeps everything in sync and up to date on my two work iMacs.