Update 2014-07-26
Update 2014-07-26: I found a use of "effective altruist" on one of Eliezer Yudkowsky's 2007 Overcoming Bias posts (now redirects to lesswrong): "If you want to be an effective altruist, you have to think it through with the part of your brain that processes those unexciting inky zeroes on paper, not just the part that g...