Where web sites come from: Paper mockups of Flickr, Twitter, etc.
There are a few other paper prototypes to check out as well. In some cases the paper sketches look strikingly like the finished product. In other cases, they just look like a blur of lines and arrows.
Most of the images were found via Flickr. Odds are if you spend some time searching, you can find a few other gems. Let us know if you find anything good in the comments!
[via Boing Boing]