An attempt to match as closely as possible the artwork in a modelling viewport and the game engine in which they will run. In most game development pipelines getting the art in a 3D package to match the exported art running on various game engines takes many many iterations. Even if your not using the Blender Game Engine as your target it's a very fast way to prototype your artwork, GLSL shaders, animations, physics simulations etc.

Download a work in progress movie here http://www.box.net/shared/static/i765z4tvbm.avi

Or watch a lower quality version here http://www.vimeo.com/5607407





You can download a short movie of the Land Rover showcasing Blender's real time GLSL capabilities in a standard viewport here http://www.box.net/shared/static/j521nplpfz.avi (6 meg)
Or watch a lower quality version here http://www.vimeo.com/7088485

Pre rendered movie of Land Rover moving through water
http://www.box.net/shared/static/mk4xuyvvo5.avi (7 meg)

Land Rover game engine test drive
http://www.box.net/shared/static/hlp38z80g5.avi (7 meg)

Land Rover physics debug mode
http://www.box.net/shared/static/n9xozluqdh.avi (25 meg)