We first released our 'Guide to Greener Electronics' in August 2006. The guide ranks the 14 top manufacturers of personal computers and mobile phones according to their policies on toxic chemicals and recycling. This is the second edition of the Guide.Acer and Lenovo are the latest of the top computer makers to commit to stop using the worst toxic chemicals in their products. Along with Motorola these companies are the biggest movers. Disappointingly for Mac fans, Apple has dropped to last place.