The United States Postal Service launched a campaign today to increase awareness and create results for energy conservation at a "Turning Over a Green Leaf" event in celebration of Earth Day. The agency, which says it wants to reduce energy use 30% by 2015, exhibited "green" initiatives at the event, including the USPS' green Web site, a carbon and lifestyle calculator, an office supplies swap Web site, energy-saving tips, and Cradle to Cradle-certified "green" packaging and shipping supplies.