I wrote a freeware Windows utility called Folderscope and deduping large folders is one of the main use cases:

Folderscope

Enjoy, Andrew.

Here is my list of Feature Requests:

• Extend sensitivity into Infrared Spectrum
• Extend sensitivity into Ultraviolet Spectrum
• Zoom: Increase optical resolution, then digital zoom in and out with buttons on glasses.
• Heat mode, toggle button on glasses.

Are these pre-installed clients interoperable? Are they as easy to setup and use as typing a URL at an Internet Cafe, a friends computer or public Internet terminal? There is a big difference between making something technical possible and making it ubiquitously "click-run" and "mum-can-do-it". I would like to be able to login (in one step) to any machine and have the same interface that I have from home and work. My experience of using a computer should be dictated by me and not by my physical location.