I was working through my Yahoo! Daily Picks and I came across this one that I got back in February.
Ecological Footprint Quiz
The quiz determines how much of a ecological "footprint" you and your household leaves on the planet in order to sustain it. For example, it asks how many processed/packaged foods you consume, how much meat and/or animal-based products you eat, how much waste do you produce in comparison to others, how far you drive, how much mileage you get and things you don't think about like how often do you fly per year and whether or not you drive a motorcycle.
My household requires 8.1 global hectares (vs. the average Canadian 8.8 global hectares).
The conclusion was if everybody lived like my household did, we'd need 4.5 planet Earths to support us all, as the site indicates that the Earth can only support 1.8 global hectares.
It also provides the tools and suggestions for reducing your global footprint - reduce this, include more vegetarian meals, try to buy more produce locally, etc.
Take a look.