Fascinating video from Google's blog, showing how a blockbuster video game's design architect uses Google Sketchup. I especially like at the end where they show how they combine the same building blocks in clever ways in order to render the levels crisply.
http://googleblog.blogspot.com/2011/02/designing-award-winning-video-games.html
http://googleblog.blogspot.com/2011/02/designing-award-winning-video-games.html