At the recent E3 event, John Carmack showed off his new engine called iD Tech 5, which will be used in an upcoming title called Rage. He spoke extensively about a thing called a MegaTexture and hot it would free artist because they could use unlimited amount of textures without it affecting performance. It sounds very intriguing, but I could not find any indepth technical information on the internet about or even musings on how it might work. Does anyone here know about MegaTextures? Can you point me to some resources?

If you have not seen the John talk about Tech 5 yet, then have a look @
http://www.gametrailers.com/game/4440.html

Not that I'm likely to use it in any game soon, but it's always good to know.