The High Impact Network (THINK) is a new group that organizes meetups for people interested in effective altruism. They've got meetups happening this fall in dozens of cities - find out if there's one near you.
Giving What We Can is running groups in several cities this fall. Jeez, those Oxford people are on a roll.
I believe 80,000 Hours will also be running some groups this fall, but they don't have details up yet. The Life You Can Save is looking for leaders for new student groups.
Lastly, Jeff and I are having a dinner/discussion on effective giving September 14th at our house. If you'll be in Boston, let me know.
I've said this before, but I'm totally happy to talk/email/skype with you. Some key people did that for me when I was discovering this movement, and it really made a difference to me. Questions? Arguments? Go for it. juliawise07(at)gmail.com