Need to determine your carbon footprint? If you're in the UK, you're in luck. The government, specifically the Department for Environment, Food and Rural Affairs along with other agencies and technology partners, cooked up the Act on CO2 Calculator to help individuals work out their carbon footprint.

A flash widget helps folks account for the carbon output of their homes, appliances and personal travel and spits out the results in "tonnes per year."

Though reachable from the US, the widget has a distinctly British flavor and caters to their standards accordingly. For instance, right off the bat you're asked where you live by entering a postal code, which for non-Americans is often a fun mix of number and letters (I used the example provided to put it through its paces).

For a calculator more suitable for US users, and a lot more concise to boot, hit up the one hosted by the site for "An Inconvenient Truth".