Vista - Finding UNIQUE set of files from multiple locations

Hi,

I need an utility to find UNIQUE set of files across a specified set of multiple locations (either drive letters or folder paths). In short, if the file occurs ONLY at ONE of the locations provided without being present at any of the other locations, I need to identify these files. This is to ensure that I back them up as soon as possible.

I need to use this to find files that are not available in my backup sets across multiple locations. Normal utilities for duplicate finder only finds duplicate files across multiple locations and not the other way around.

Folder synchronization utilities finds missing files but they do not accept more than two locations at a time and hence cannot be used to find unique files across more than two sets of locations.

Thanking in advance,

Evfu