I have several existing photo sets in my Flickr account. I would like to setup now Flickr publishing with Lr4. How do I make those sets known to Lr4 to work with in future or do I have to load them again through Lr4?
Jeffrey's more expanded Flickr plug-in has some facilities for linking existing Flickr uploads with photos in your LR catalog http://regex.info/blog/lightroom-goodies/flickr
Or are you just wanting to be able to add new photos to existing sets?