I took the "eco footprint" test, and found it odd and extremely limiting. It asks you things like what city is your weather like, and the closest to me was NYC, but we're colder and further North.

It asks how big one's house is, but doesn't ask if your house is insulated.
It doesn't ask what kind of heating system you use.
It doesn't ask whether you use air conditioning in the summer, etc., etc.
It doesn't ask what temperature you set the house to in colder months.
It doesn't ask about how many major appliances or computers you own/run daily.
It doesn't ask if you recycle anything, or how much you recycle, or what you recycle.
It doesn't ask how big your lawn is and if you have to water it, and how many months of the year.
It doesn't ask if you compost.
It asks if you have more or less waste than your neighbors - well, that doesn't prove anything. We, for example, are two people, the neighbors are 7 (parents and 5 kids), so ...

It doesn't take many, many things into account, so I don't give it any credibility, sadly.