In celebration of Earth Day 2011, the United States Postal Service, in partnership with the United States Environmental Protection Agency, issued 16 different "Go Green" commemorative stamps. With Go Green, the USPS raises awareness of simple actions each of us can take to conserve natural resources and promote the health of our environment. Each of the "Forever" stamps features an eco-tip with an illustration showing simple things any of us can do each day to reduce our environmental footprint.  The stamps convey a positive message: things we can easily do to have an immediate impact on the air we breathe and the energy we consume.