here ya go...
a few more reasons NOT to turn it off!
Reasons to Leave it On
Running Services
Sometimes, your computer performs a function even when you are not sitting at it. Perhaps it acts as your fax machine. Maybe you use it as a web server. Maybe your company uses it as a print server or file server. In these cases, in order to keep those services running, leave your computer on.
Hardware Durability
It is a fact that turning an electrical appliance on puts more stress on that appliance than keeping it running for a long time. The reason is that the initial surge of electricity through the circuits is a traumatic event (shocking, even). Your computer is an electrical appliance, and therefore constant power ups and power downs can wear out the parts before their time. If the durability of your hardware is an issue, then leave it on.
Convenience
Starting up Windows is a hassle. Sometimes you just want to sit down at your computer and be able to work without having to boot it up and wait for a few minutes. This is a perfectly legitimate desire! If being able to use your computer instantly is important to you, leave it on.
The Big Myth
People will try to tell you that leaving your computer on will open you up to power surges and electrical disasters that will "fry" your computer. This is true, but your computer is susceptible to power surges even if it is off! A power surge travels over electrical wires, and surges don't care if the appliance is on or off. Therefore, if you want to be careful, you should purchase a good surge protector or UPS (uninterruptable power source). Or, for the paranoid, you should unplug your computer altogether when it is not in use.