I'm not sure where is the best place to put this but I figure here would be a start. I currently have an iMac 24" with the standard 320GB drive. Currently I do not have any back-up solution for my pictures/documents/etc. The 2 major back-up I want is my "Aperture Library" and "iPhoto Library". What is the best way to back this up? I'm going to go out and purchase a 1TB drive shortly but do not know the most efficient way to back-up. Do I just copy the entire library over to the external drive and when I do another back-up, delete the old one and copy the new one over? There has to be a better way for this. Is there any application that will only copy over changes I made? Like if I added pictures, it would only update those on the external drive? Any help would be greatly appreciated. Thanks!