I'm actually pretty involved with the NY optimal philanthropy cluster - I'm working with Mark and Geoff on their current project. Haven't gotten in contact with the Givewell people yet, apart from Stephanie.
But despite a pretty strong Less Wrong presence in NY, there's surprisingly few people there who are genuinely passionate about optimal philanthropy. Looking to get to know the existing community better and hope it can grow.
If you know some time in advance when you'll be in Boston I'd be happy to try and schedule one of these meetups you could come to.
Julia and I have done a lot of thinking and writing about how to do the most good in the world [1] [2] but we don't have things all figured out. We'd love to talk to other people interested in optimal philanthropy, so if you're in the Boston area on Friday July 6th we'd love to have you over for dinner and discussion.
Details:
[1] Julia's blog: givinggladly.com