Two nifty websites to compute your impact on the earth:
The Carbon Counter at http://www.stopglobalwarming.org/carboncalculator.asp
calculates ways of reducing carbon emissions in your own life, and how much money you may save doing so.
The Ecological Footprint quiz looks at how much land and resources it takes to support your lifestyle, depending on a variety of factors.
There may be parts which are not applicable to every person or household, but these two quizzes sure did get me thinking! Hope you enjoy them.