American Go Association
Start up a club and register it here to advertise to Go players across the country!
Penn Go Society
Philadelphia's other Go Club - we meet once a week, every Wednesday evening, from 5:30 p.m. - 11:00 p.m. on the campus of the University of Pennsyvlania. Open to all and free!
A Korean Go server, with no English interface. When the club had a networked computer, this is where most of the players seemed to play.