Have you used Less Wrong's "Send message" functionality?
(Edit: It's a button in the upper right corner of the page you get when you click someone's username.)
Thank you. I had assumed that Less Wrong had no private messaging when the envelope icon near the top right corner of the interface took me to the reply to my first comment.
80,000 hours (eightythousand.org) is a new website associated with High Impact Careers, a Giving What We Can-associated effort to inform the public about "professional philanthropy" and the fact that you can do more good as a banker or entrepreneur than as an aid worker. It recently got some BBC press, and there's a neat new video.
Related to efficient charity and optimal philanthropy. Also see scope insensitivity.