From the Park Slope Buy in Bklyn Campaign, which brought us those honor system yellow umbrellas, comes news of a Snowflake Celebration, a late night for Park Slope retailers on December 13. Rebeccah Welch, who is helping to organize the effort, told us that the entire effort has been put together by volunteers over the course of the last few weeks. In the meantime, the umbrella effort, about which GL had the first published report, continues getting coverage. Yesterday, Jake Mooney had an amusing item about it on the CityRoom site that had a lot of links to other honor system programs and his City Section story about it has already been posted. The Great Park Slope Umbrella Experiment is clearly one of those stories that touches many chords, particularly in its challenge to basic precepts that people will simply take umbrellas. (Although the experiment seems to be going well so far.) As a marketing tool, it has proven to be a big success both for the Civic Council and for the Buy in Bklyn effort. The poster for December 13 late shopping night is below.