I'm a firm believer in having a small internet footprint.  As such, I have no twitter, no facebook, no myspace, no nothing of anything.  There are very few pictures of me online, and those few are ones that my wife put up on her own social website.  If I google my own name, I come up with only two websites that are actually related to me.
 
I have nothing against social networking or the people who use it, I simply have no real reason to participate to any great extent.