Put Your Computer to Sleep-Save $75

Set your computer to sleep—not just the monitor, but the hard drive, too—so that it automatically dims after 10 minutes of nonuse.
Cost: It may doze off when you don't want it to and you'll have to punch a key to wake it up.
Savings: $75 per year off your electric bills.
Bonus: Like people, screens and hard drives age more gracefully with plenty of rest.