This program allows you to export game scenes to a model format. Only works on DX 9, it won't work on OpenGL and DX 10 games.
It just reads all the geometry of the game you're running and saves it on .obj and .3ds format. It also saves textures of the scene you're playing. Very useful too for mappers.
http://www.deep-shadows.com/hax/3DRipperDX.htm