Windows only: Windows ships with some solid power management options, but it misses the mark on one issue: Most of us need different energy-saving schemes at different times of the day. SetPower adjusts your power management settings on a user-specified schedule.
Once you've downloaded and installed SetPower, just fire it up and start scheduling different power management options based on the time of day. As the cheesy infomercial-style video above points out, SetPower is perfect for giving you the performance you want when you need it without wasting energy when you don't need that extra performance—potentially saving you a decent chunk of money on your electricity bill.
If you're in bed after midnight during the week, for example, put it on a serious power diet to make sure it's sleeping or hibernating quickly. If you spend an hour or so on the computer in the morning before heading out to work, adjust your power management settings for a little more performance over energy savings. If you're at work from nine to five, dial it back to another power-saving, quick-to-hibernate setting. (You get the idea.)
Any power scheme can be applied individually to any day of the week, starting at whatever time you want.
SetPower is a free download for personal home use, costs $US5/license for your workplace to buy it, Windows only.