I’ve written about this subject ad nauseam - here, in my book, in articles. Three posts:
Invasion of The Baby Boomer Pod People
Invasion of the Baby Boomer Pod People Returns
Sleepy Baby Boomer Internet Villages

Here’s the comment I left on The Boomer Consumer Blog post.
Then Peter Himler, numero uno Flack (hey, he describes himself as such – at least the ‘flack’ part – ‘numero uno’ is my description), also talks about social networking sites, and tells a great story about his experiences with one:
Business networking sites - of course, it's simply good business to join some. But as far as general interest social networking sites, when Peter mentions “content and utility” I think he means relevant articles, videos, and new media - along with finding products and services of interest to him.... Within a day, I started receiving messages from some of the lonelyhearts whose less-than-appealing head shots peppered the site .... The next day, the come-ons from paid escorts arrived. I cancelled my membership and struck the site from my new business prospect list ... I'm convinced that there are many social networks -- some I know, others I don't -- with the kind of membership, content and utility that will accrue to me personally and professionally. I'm just scratching my head on which ones.”
That's not social networking.