Quick Online Tips: The Great Flickr Tools Collection
flagrantdisregard.com Flickr Toys
BigHugeLabs: Do fun stuff with your photos
Photo Effects and Photo Editing with One Click - BeFunky.com
Pixenate - Edit photos online, fast and easily - No plugins required.
Canva - Amazingly simple graphic design for blogs, presentations, Facebook covers, flyers and so much more.