FlickrDeDupr is an application to automatically identify duplicate images in a Flickr account. It's nothing fancy and relies on the Title being the same along with the DateTaken attribute. This did the job for me to clean up the mess from the Windows FlickrUploadr which has a habit of failing to upload and then offers you the option to "Try Again" but fails to remove photos that had already been uploaded before trying again. Hopefully it works for others to help clean up their accounts.
Originally released by me at http://flickrdedupr.rpgaddicts.net/ I'm making the source code available in case someone else wants to maintain it.