So, in the nealry 2 years I've been involved with flickr I've seen several memes come and go, the current one HDR, sadly shows no sigh of abatting. The newest kid on the block on the other hand, is "Through the viewfinder". Some interesting results, and a nice idea that if elegantly applied could produce some great results. Even Kottke is waxing lyrical about it the idea of digitally capturing a scene though an old camera.
Some flickr clusters on the matter.