Since 1998, GeekNightPittsburgh has been a bimonthly gathering of Pittsburgh Geeks to gather, commingle, network, and generally discuss the state (exuberant or dismal) of the IT world in Pittsburgh. Formerly held at the Foundry Aleworks on the Strip, GeekNightPittsburgh recently moved to the Valhalla when the Foundry closed.
Official site: http://www.pghgeeks.org