Duplicate Photos

Hi Everyone i am new to this Site.. i am having a problem with iphoto it seem i have very many duplicate photos and was wondering if there is a way of finding all the duplicates and deleting them without having to sit for hours going through every single one?
also is it possible to then transfer all the remaining photos to an external hard disk drive therefore freeing up my memory on the Pc.. i would appreciate any help on this matter.. Many thanks C

Brattoo Software makes a highly-recommended $8 shareware product called Duplicate Annihilator.

I've also been trying to eliminate duplicate files on my MacBook Air. I have a lot of duplicate photos. I'm hesitant to delete the "duplicates" without knowing what it might affect. Anyone have any idea what this file path means:
"/Library/ApplicationSupport/iLifeAssetManagement/assets/sub/" which leads to another folder with the duplicate jpg photo.

I want to be sure if I'm deleting it, I'm not affecting an app or as result I delete it completely. My suspicion is that this file path represents pictures in "Photo Stream." Would it be a big deal if I delete it from Photo Stream since I have the "original" in my iPhoto Library?

Thoughts?

You are playing with fire.

I think it's a lot better to live with a few duplicates (easy method to safely remove dupes already detailed in my previous post, did you read it?) than it would be to lose data ... and that's EXACTLY what you're about to do.

Weight the risks and benefits. I know which way I'd go if I wasn't 100 percent sure ...