First, Getting Green Done from Greenbiz discussion how to get companies past the barriers to better business practices.  Some good food for thought in there.  Also, check out how to better mobilise initiatives to improve branding and take advantage of new opportunities by Tamara Giltsoff on PSFK.  One particularly useful thought for companies to keep in mind:

"...educate your audience around specific issues (best related to the impact of your sector – water, energy, energy consumption, transportation etc.), present an alternative vision for the future, invest in it, create new markets by becoming part of the solution and then own the market."