StarCraft II: Wings of Liberty , the first chapter in the sequel to one of the most wildly successful computer games of all time, went on sale today. It’s available in retail stores and as a digital download for Mac and Windows computers.

Today we are celebrating Mashable’s fifth birthday. Thanks to our readers and advertisers, Mashable has come a long way since Pete Cashmore first launched the site on July 27, 2005.

Seesmic has just updated its Seesmic Web app to include support for Facebook and LinkedIn . The new version also includes a refined interface and a faster backend. Like HootSuite and Brizzly , Seesmic Web is a tool you can use to manage and monitor your social networks all from within the web browser.

Stieg Larsson, a Swedish journalist and detective novelist best known for his Millenium trilogy, has become the first author to sell more than 1 million e-books in the Kindle Store. The three books in the posthumously published trilogy — The Girl with the Dragon Tattoo , The Girl Who Played with Fire and The Girl Who Kicked the Hornet’s Nest , are all among the Kindle Store’s 10 bestselling books of all time. As of March 2010, the trilogy has sold more than 27 million copies (physical and digital) in more than 40 countries.

Felicia Day and her lovely cast members are back in action for Season 4 of The Guild , the web-based comedy series that revolves around a World of Warcraft -like game and the lovable nerds who play it.