Social Networking and Constituent Communication: Member Use of Twitter During a Two-Week Period in the 111th Congress, by Matthew Eric Glassman, Jacob R. Straus, and Colleen J. Shogan, Congressional Research Service 7-5700, R40823 (September 21, 2009). [posted on politico.com]

See also:

• For GOP, revenge is tweet, by KENNETH P. VOGEL Politico (9/23/09)
• Tweet All About It: New Stats On Hill Usage, By Andrew Noyes, Congress Daily "Tech Daily Dose" (Sept. 23, 2009).