The EPA's Energy Star recently launched an online tool to help individuals assess their current energy use and find easy ways to become more efficient at home.

The interactive tool uses this cross-section diagram of a single-family house. You can click on any room for a scaled-up image with stars on each of the devices and structural elements in the room where energy efficiency improvements can be implemented. For example, in the living room, close the flue damper tightly on the fireplace to keep hot and cold air from escaping; seal holes around wall outlets with an inexpensive outlet gasket; apply caulking and weather-stripping around doors and windows.

The service is a heavy-hitting publicity vehicle for Energy Star, but [and] also a user-friendly, accessible tool for learning about easy ways to save money on energy bills and contribute fewer greenhouse gases to the atmosphere. They also have a comprehensive list of tips, organized by room, where you can locate specific solutions.