These guys have already been mentioned in British Parliament, so maybe I am the only one who hasn't heard of them, but wow, what a fantastic spoof of carbon offset schemes. And it addresses an important and overlooked issue with carbon offsetting and trading - the human behaviour element. How is it likely to make people behave? Probably something like this:
Check out their website here. Check out the "Our Projects" page. It's a riot. And you can just see people doing these kinds of calculations with their driving and flying in a carbon offset context also.