Aaaaaaaaaaahhhhhh! it's raining paper crafts today. The Webdude has just left a note about a "hidden model" on his Angels of Neon Genesis Evangelion page - it's the Jet Alone paper craft model.
"Jet Alone is a nuclear-powered, unmanned robot created by an independent corporation for the Japanese government with the intention of supplanting the Evangelion units. Unlike the Evas, Jet Alone has an on-board nuclear reactor, so it can function without external power indefinitely. However, its control systems were tampered with by agents of NERV and the unit's first public demonstration nearly ended in a nuclear disaster. The project remained unsuccessful after the incident." - wikipedia
Note: To download this model, look for the moving eyes!
Jet Alone - [Download Page] [If you can't find it click here]