Heard this month from a company called SetPower, which offers two flavors of a utility that allows you to harness and make better use of a Windows computer's in-born power management capabilities.
The company has just released a new version of its enterprise edition (list is $5 per machine); the most notable new feature is a function for creating reports that provide an aggregate view of the power saved through its Power Schedules. It also provides a free version that people can use to try out the software. SetPower encourages people who use the free application to evangelize the product at work.
Here's a blow-by-blow review of the SetPower software from the MakeUseOf.com Web site. Sorry, I can't try it out myself as I only have a Macintosh.