Not sure whether this application is right for me or not. It’s called FlickrSync.

FlickrSync is a freeware photo synchronization application for flickr users. It displays your local folders and your flickr sets and it can establish synchronization rules between them. This way you can manage all your photos locally and FlickrSync will keep them updated in flickr.

Available for Windows XP SP2 and .Net 3.0 only.