Windows only: Free system tray application Edison helps save energy and money by tweaking your PC's power settings on a schedule. Edison allows you to set different energy preferences for work and non-work time, then choose the times you want each profile to run. The power settings determine how long your PC should wait before turning off the display, powering down your hard drive, and suspending your computer. After you set your preferences, Edison also estimates your yearly savings in terms of money, energy, and CO2 emissions. Edison is freeware, requires .NET 2.0 and an email address for registration. If Edison's whopping 45MB memory footprint is too high for your tastes, check out previously mentioned LocalCooling. For more green PC tips, try our best tips for going green with your PC.
Edison [via Download Squad]