We've seen what Gmail, Twitter, and Delicious look like in paper, but what about Flickr, YouTube, and others? Sean Flannagan over at Deeplinking has put together a gallery of site prototypes that have been constructed out of paper. While tools like Adobe's Thermo and the freshly launched Balsamiq are making this less of a necessity, some of the best ideas are scribbled out on wet cocktail napkins right?
One of my favorites from the collection of Flickr places (coverage), which I've put side by side with its final result below. Be sure to check out the original version on Flickr that houses the massive, 2,000-plus pixel-wide size.