The Marine Corps has decided to embrace social networks and is now allowing units and individuals to use social media (and access the sites, which were previously blocked on Marine networks).  Wired describes this decision as an about face because the Marines had banned Twitter, Facebook, MySpace, and other sites last August.

This is probably the most interesting passage from the Wired article, a quote from a Major who worked in the Haiti relief operations:

The wars in Iraq and Afghanistan are fought on classified information systems. While an operational necessity for these conflicts, most disaster relief partners, to include a majority of the US Embassy staff, can neither see nor access classified material. During the initial days of the relief operation, the ability to pass timely and accurate information was arguably as important as the availability of food and water. In the initial weeks of Operation UNIFIED RESPONSE, Blackberry text messages became the primary means of communication, chiefly because they were the simplest and most reliable means of corresponding with the host of US Government agencies, United Nations offices, and Non-Governmental Organizations (NGOs) coordinating the relief efforts.

A city manager addresses the issues surrounding civic engagement and social media.