I think Citigroup is one of the worst-run companies in America, if not the world, but I don't think their private jet usage is the problem there. In fact, perhaps it would have been better for us all if they had spent more time running around the world and seeing the sort of mess they had been creating (one need only see the tract-home-filled foothills of Orange County, California in 2004 to understand there was a bubble).
This is the absolute worst time for us to start getting morally indignant over others' consumption. The more we do this, the worse it will be. Any purchases that lead to gains in productivity need to be celebrated -- that's how money swirls through the economy and gets us out of this mess!
Oh yeah, and people who work in corporate aviation departments tend to be really cool.