Over the years, I have had many computers, and many photo libraries. Somehow, I didn't keep them all in order, so I have Picasa on my PC with a lot of photos, I have iPhoto on my Macbook Pro, and then I have a couple of folders on my external hard drives with backups of my previous original 1st gen Macbook Pro photo library, as well as a backup of photos from my old PC. To put it simply, I have a complete and utter mess on my hands! What is the best way for me to take all the photos I have in my existing iPhoto library, and then add in all these other folders without creating an even bigger mess for myself? Should I do all the de-duping outside iPhoto first and then import everything? What are the best programs to de-dupe folders? And I'm not talking "show me the difference", i mean "show me all the files that are in that folder (and all subfolders) but not in this folder (or any of its subfolders).. I know iPhoto has an option to check for duplicates when you upload, but I've found it to not work 100% of the time, and I've also found that if there are any differences that it might still import the duplicate. Any help would be appreciated, I am overwhelmed at the number of folders and files I have to try and sort through and clean up this mess!!!!