Andy Carvin of The Digital Divide Network has a podcast available on his blog of his "keynote speech at the University of Missouri Scholarly Communications Conference". He also has a powerpoint presentation of his speech you can download to follow along with at home.
Andy notes in his talk that there is a direct correlation between income and education and who is and who is not online. He also remarks that content needs to be both locally and culturally relevant, as well as available multilingually, for people with different literacy levels, and accessible to people with disabilities.
His talk is an important reminder, as we use these online spaces, about how long we still have to go as a nation and a world towards bridging not only the digital, but the educational, economic, political, and other increasingly growing social divides between the "haves and have nots".