Have an iPhone or an iPod Touch? If so, there are applications that you can purchase to help green your lifestyle. Applications like iGas lets you search for the cheapest gas prices in a zip code; if you purchase the "A Real Tree" app they will plant a real tree in one of 12 countries fighting deforestation around the world; The 3rdWhale app helps you to locate "green" businesses in your area. There are plenty more cool "green" apps out there.
Here's a video about these green apps: