CEOs at the top companies in the U.S. are dramatically disconnected from the social networking phenomenon, according to a research report released this week by UberCEO.com, an online news and discussion site that focuses on CEOs at major companies.

The study found that only two CEOs from Fortune magazine's list of the Top 100 companies have Twitter accounts and only 19 have a Facebook page. And none of the 100 CEOs were found to have a personal external blog...