Raph Koster points us to a useful piece of kit: OGLE, the OpenGL Extractor, is a tool for extracting 3D models from OpenGL applications. By sitting between the application and the OpenGL library, OGLE can effectively take 3D screenshots--and the possibilities for gaming are immense.
The examples given by OGLE's developers include transforming a World of Warcraft avatar into a real statuette using a 3D printer, and importing Google Earth's 3D data into Maya for further editing. The Google data could be used to make a realistic world model for a game set in modern times; transferring character models between games could give rise to some fantastic FPS mods and some imaginative machinima.
Copyright issues may lead to the software being restricted, but for now: let the hacking commence.