gastax.org

Voluntary gas tax projects

voluntarygastax.org -- Shenandoah Valley gas tax project

gastax.org -- VGT project, now defunct (2001-2006)

Carbon footprint calculators

safeclimate.net

myfootprint.org

Advice about buying personal carbon offsets

Carbon offsets: Four questions to ask -- a CNN article

Non-profit organizations that sell carbon offsets

MyClimate, by Sustainable Travel International -- home, road, flight,hotel -- renewable energy, energy efficiency

Carbonfund.org -- home, road, flight -- renewables, efficiency, reforestation

The Nature Conservancy -- food, home, road, flight -- deforestation, emissions, environment

LiveNeutral.org -- road, flight -- emission reduction credits

Green Tags, by the Bonneville Environmental Foundation -- home, road, flight -- wind, solar or blend of two

For profit organizations that sell carbon offsets

TerraPass Inc. -- home, road, flight -- renewable energy,efficiency,biomass

NativeEnergy, LLC -- road, flight, rail/bus -- wind, farm methane

Climate Friendly -- home, road, flight -- renewable energy

e-BlueHorizons, LLC -- home, road, flight -- emission reduction, reforestration