There are a few Park Slope & “Surrounding” Slope groups working with Brooklyn for Obama that are having get-togethers soon. The next one is on Wednesday next for the Gowanus/South Slope/Sunset Park folks. For more info, go here.
The Park Slope group is pretty active–to check it out, go here. And finally, The Obamathon is May 12th in Battery Park. Learn more here.