earthhour: Make the switch to energy efficient LED bulbs! (source) What an excellent infographic on how you can save money and be more energy efficient if you were to switch to CFL or LED bulbs in your home or business.
The world's first Active House stands at the crest of an estate. Its south-facing roof is covered in solar panels and solar cells, which between them harness more than enough power to keep the occupants warm and the appliances running. In around 30 years' time, if designers have got their sums right, the excess electricity flowing from the house into Denmark's grid will have cancelled out the energy costs of building it, leaving a non-existent footprint on the earth's resources.