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As the last group in CS I acitively use is the local Hamburg group, it is obvious to start the same thing here. Every local or wannabelocal or however interested person is welcome to join and fill it with life. Especially if you're interested in doing more than just join let me/us know, so we can have a local meeting and get things started.
EDIT: The connection to the group doesn't work yet, so here you go: http://www.bewelcome.org/groups/51