Supr Flickr is a new Firefox extension that's a hodgepodge of small changes that make the site better suited for power users. I like it because it quietly brings many of Flickr's deeper features front and center, keeping you from having to dig around too much to get at them. Things like viewing multiple sizes of a shot, remembering formatting tags when writing descriptions and replying to comments, and grabbing a photo's source link are all made simpler.
Among its handier features, the add-on includes quick links to the third-party Hivemind search engine, which offers search filters Flickr's own search engine does not. It also vastly improves the ease in replying to other users comments, both on individual photos and in group discussion threads by supplying links to give the conversation threading.
Users may want to install this alongside Gina Trapani's Better Flickr extension, which gives you many of the same options and adds in things like a photo magnifier and improvements to viewing thumbnails, while letting you select which features you want to turn on and off.