Sometimes the simple things make for meaningful change, like finding and unplugging unused equipment:

9 ) Waste Management. AT&T is always looking to minimize waste. For example, AT&T remains dedicated to reducing the amount of e-waste generated. In 2010, AT&T collected over 95,000 computers, servers, and monitors for recycling, reuse, and donation. AT&T also has a strong relationship with Xerox Corporation to do a review of all printing devices in AT&T office buildings. With Xerox Corporation, AT&T was able to remove over 19,000 devices from almost 3,000 locations, reducing energy use by more than 35 percent.

http://blog.cleantechies.com/2012/05/29/top-ten-sustainability-initiatives-of-att/?goback=%2Egde_59930_member_119596152