I found a surprising number of websites giving advice on how to disappear.
http://www.skeptictank.org/hs/vanish.htm
http://www.escapeartist.com/efam/45/Disappearing.html
How to Disappear from Facebook and Twitter
http://www.time.com/time/business/article/0,8599,1954631,00.html
Here’s a great story about a writer for Wired Magazine who tried to disappear