The Open Science Grid Operations Center will be performing maintenance on the OSG TWiki (twiki.grid.iu.edu) server on Wednesday, May 20 2009 from 12:00 to 15:00 UTC. The TWiki will become read-only at 12:00 in an effort to ensure no outages occur during editing. The TWiki may experience intermittent connectivity starting at 13:00 UTC while a DNS change propagates. Once the change is done, we will reactivate editing on the TWiki and announce the end of maintenance to the OSG Community.