Tomorrow, April 22, is Earth Day 2011 and the global organizers of this annual celebration of our planet are once again asking us all to make a pledge to help achieve “a billion acts of green.” Now, we all know that, as the U.S. economy’s largest consumer of energy, the Federal government is grappling with significant energy issues – but it’s not all bad news. From the multiple benefits of cloud computing, building information modeling (BIM), virtualization, and smart grids to simple acts like putting lighting controls in the hands of office workers, the federal government is already achieving specific gains in its sustainability and green efforts as mandated 2009’s Executive Order 13514. So, in honor of Earth today we picked our “best of” articles and insights that show just how the public sector (and those that serve it), with the help of technology, can and is, going green.