hypocritical? Yes.
But I'm not any more worried about the carbon put out by the Live Earth concert than I am any carbon put out by anyone or anything. It's when they want to put a price tag on it (well, anymore of a price tag...) that bothers me.
I must say though, I think it's laudable that folks in the Green movement strive to achieve carbon neutrality. Here's to wishing them success in their endeavor to stop their own carbon emissions.

It will make life sooooo much easier for those of us who remain.
I, however, hope to be emitting carbon in various forms for many years to come; and I wish the same to the sensible among you as well.