My dad is a photographer who is understandably paranoid about losing his photos to a HD crash. He stores his data on an external HD and then periodically backs them up to DVD. To me this seems tedious and I'd like to find a (more) automatic, cheap solution. My idea is to use my NAS (a ReadyNAS NV) to allow him to back up his files from his house to my house. That would make things very secure by having the backups in an entirely different location. He is not particularly tech-savvy, so I need his end to be pretty simple and easy to use. We are both running Windows, and I can set up a machine to be always on (at my location, where the NAS is) and use a service like dyndns.com to have a subdomain that always points to my home IP.
Any recommendations on Windows software that might make it easy to backup his hard drive to my NAS via the Internet?