One of the ways you can support the environment and not cost you any money is Better World Club– an eco friendly car club that donates 1% of their annual revenues toward environmental cleanup and advocacy. I should say not cost you any money if you are already a member of AAA.
They offer the usual travel discounts, 5% on renting hybrid cars, other event discounts, car and bicycle assistance, carbon offsets, free maps, insurance and gas rebate coupons. I really like their section on Eco Friendly Travel Tips. Best of all, they don’t use your money like AAA to lobby in Washington for more roadways and against mass transportation.