Saw this article at the Times a few days ago. But only dropped by here today. It's relevant.
http://www.nytimes.com/2012/02/05/opinion/sunday/living-alone-means-being-social.html?scp=1&sq=living%20alone&st=cse
And the biggest surprise for me is not that single person households are higher than ever in America, but that those percentages are so much greater in most other industrialized countries.
The graphics are very good as well. You can find how your census tract compares.
Enjoy!