There was a bumper sticker on a car that announced it
had redeemed its carbon footprint by buying a
carbon offset at TerraPass.
I logged on today and it is really easy to plug
in the year, make and model of your car, and
estimate the number of miles you drive a year.
It immediately tells you the number of your
carbon footprint and gives you the
price for a year's offset. Mine was $59.50.
If I buy the offset they will mail me a decal
for my car. The website gives detailed information
about where the money goes, and you can choose
between various options such as wind energy.