After input from many of you guys and the NYC group, I am announcing planetrationalist.com
There's a lot of different directions this sort of idea could go in, but I figured that this could be a good-enough first effort.
Enjoy, and let me know what you think.
Hmm, I was wondering how much people used those things. Do you want just twitter + email? Facebook?
All of the above, I'd just install some basic set of sharing buttons. Email, twitter, facebook, maybe Google+.