Tiny Houses: How small would you go?

[QueenBee]

http://www.cnn.com/2012/09/21/living/sma...=allsearch

For some oddball reason, the latest trend has been for tiny (micro) houses or apartments..especially in the big cities. But also in the country. People seem to be downsizing big time. The above linked article has some neat pictures. I am adding some more.
How small could you go with out going totally bonkers? If I were alone, I actually think I could do it. I am a bit of a minimalist anyway.