if you're on linux, there's rapid photo downloader

I think the downthemall browser addon can do this

similar situation a while back. I spent a couple month off an on, tagging all the photos to easily find in either shotwell or digikam. they're all in the same folder and new photos get tags as they get added. I took the tag approach because you can add pretty much an infinite number of tags to each photo. did that instead of trying to figure out where photos with multiple people, etc.. should go in an organized folder structure without having duplicates