I saw the video a few days ago here:
http://tinyhouseblog.com/
Lots of ideas for staterooms, survival pods, etc. The primary motives of most of the contributors seem split between ideological (reduce your footprint, stop wasting resources, etc.) and practical (youth, debt, poverty, divorce, etc.). Articles and links about how to downsize, simplify and organize, for those interested.
Personally, I've been trying to downsize my book collection for years. I sorted them into Give, Keep, and Maybe. "Give" were books I didn't like, mostly impulse buys, or good intentions (exercise, diet, etc.). Some I just put in a collection bin. Others I gave to groups that might have an interest in them, like my old theater books. "Keep", well, duh. "Maybe" are in a big pile by my bedside. I look at them, try to read them. If I like them, into the Keep pile. If not, Give away!
Even then, I still couldn't fit into one of those cubes.