I’m often to be found hanging around on Flickr, most often in one of the Utata, Flickr Ideas or Flickr API groups. As well as storing my photos on Flickr, I also spend a fair bit of time playing with the API and am the author of a book on the subject, Flickr Mashups (it’s really good, go buy a copy now).
I have created a number of tools, applications and web sites that make use of the Flickr API. Here are a few of them: