An average person who uses a computer would usually just walk away from it when your done, or if your gone for an extended time (and they know about it in advance) they'll probably put it in sleep . I (myself) use to keep my computer on about 8 hours a day, just saying I'll comeback to it later. Well there are many ways to save electricity.
Step 1: CRT versus LCD
Many people and businesses use CRT monitors because they might have it from an old computer and say "Hey, why buy a new monitor works just fine, I'll save money."
Facts about an average 17" monitors (using the average kwh price of 9.86 cents, you can look at the map):
1) Electricity used: 80 watts
2) Money spent keeping the monitor on for 8 hours cost about 6.4 cents per day, which adds up to 23.36 dollars a year.
3) Cheapest new I could find off of Newegg was 125 dollars.
4) They're fat and ugly and take up half of your desk (well that was an opinion)
1) Electricity used: 35 watts
2) Money spent keeping the monitor on for 8 hours cost about 2.8 cents per day, which adds up to 10.08 dollars a year.
3) cheapest new I could find off of Newegg was 150 dollars
So if you have a CRT and switch to a LCD an average would save 13.28 dollars. If you had a choice of buying the CRT and a LCD you would only lose 11.72 dollars. A cheap price to help the Earth and have more room on your desk.