Brittin Witzenburg is worldchanging. As the newly-hired resource conservation manager for the Olympia (Washington) School District, she's already saving schools money by pointing out ways to work sustainably:

[T]his week she's working on installing new thermostats in 43 Olympia school portables, which will save the district an estimated $6,435 annually. The new thermostats -- which the district is getting free through a Puget Sound Energy rebate program -- can be programmed for 365 days. That means she can set the devices to automatically turn down during breaks in the school year.... Meanwhile, Witzenburg plans to present a new policy to the Olympia School Board next month that would formalize guidelines for lighting, heating, air conditioning, water consumption, solid waste and recycling. The district estimates that in her first year, Witzenburg will find savings of about $75,000, or about $10,000 more than the cost of her salary and benefits.

We often focus on the big players here -- politicians, CEOs, NGO leaders, innovators and advocates -- but it's important to remember that some of the most important work in the world is being done in the trenches, one thermostat at a time.