PathSync (GPL)
an interactive directory (path) synchronizer for windows
PathSync can analyze two directories and show the user a list of differences between the directories.
The user can select what actions should occur (which files to overwrite, which to delete, which to ignore), and allow PathSync to synchronize.
I use this in a jiffy, it works by comparing the dates and file sizes of the files; and what's there or missing; and just copy/delete to make a clone of the source.
Furthermore, it's portable (just copy the directory) although I am not sure if it leaves anything behind in the registry
Bonus is that it can save/load the settings that you use before.
Weekends were made for programming. - Karl Lehenbauer