Better Hold Your Breath...
The World Wrestling Federation, ehmmm, I mean World Wildlife Fund has a very graphic illustration of how much carbon monoxide is produced by a car each day. Wow!
It's part of the WWF's campaign to highlight 20to20 or "20 ways to reduce your carbon by 20%" website at http://www.20to20.org/ which is full of cool little tips to make your footprints lighter. Some have even been mentioned here before.
In true Web 2.0 fashion you can submit our own tips.
So time to start getting creative. Like stop using pencils.