One of my favorite examples of the positive impact that IT can have is to cite UPS, which uses an algorithim to optimize the routes of delivery trucks to minimize fuel use and maximize driver productivity.
So first, I was pleased to come across some reporting on what UPS does, titled "Why UPS Trucks Don't Turn Left".
But even better, I met two guys at an event in Atlanta the week before last, who have been responsible for the operations at UPS's data center.
They told the story of examining the operations of the center years ago to find cost and energy savings, primarily attacking airflow opportunities - well before the current focus on efficiency took hold.
Their strategy was quite simple: they compared the total airflow needed by equipment (using nameplate ratings and specs) with the total airflow provided by the cooling equipment. Turns out that like many enterprise data centers, they were over-provisioned by a factor of greater than three.
They commenced efforts to plug leaks, instituted blanking panel installation policies, and started to put cooling units into standby, saving hundreds of thousands of dollars in annual energy costs in the process.
So my favorite story remains so: UPS uses efficient IT to deliver real on-the-ground environmental and productivity benefits. That's a blue chip case study.