The Pew Institute has been researching technology and various demographics.

The study in January covers internet, broadband & cellphone statistics:
55% of American adults connect to the internet wirelessly, either through a WiFi or WiMax connection via their laptops or through their handheld device like a smart phone. This figure did not change in a statistically significant way during 2009.

The most recent study (released Feb. 3, 2010) focuses on young adults and social media:
Even as blogging declines among those under 30, wireless connectivity continues to rise in this age group, as does social network use. Teens ages 12-17 do not use Twitter in large numbers, though high school-aged girls show the greatest enthusiasm for the application.

more at
http://www.pewinternet.org/