Promote your work's Challenge team and help your coworkers save money in their homes.
Why You Should Do It
Having an Energy Challenge team for your business and spreading the word can do a lot of good - it shows that your place of employment is interested in energy efficiency and conservation, it helps employees reduce energy use at the office and at home AND it shows how truly awesome you are.
What It Costs
Free! Although if you bring in some brownies with the Energy Challenge info, more people will probably show up.
Make It a Family Activity
These things are always easier with a few people. Start with your business's Green Team; if you don't have one, see if you can find a few allies and friends who would be interested in starting an Energy Challenge campaign. Then you can divide the work up and get more done.