PC World: "Overclocking refers to pushing your computer components harder and faster than the manufacturer designed them to go. The initial pitch is seductive: Buy a slower, lower-cost CPU; juice up the clock speed; and presto! You have a cheap, high-end processor.
Of course, it's not that simple. Overclocking can certainly speed up your system (and save you some cash in the process), but only if you do it right.
We're going to talk about some of the basics of overclocking--what it really is, some of the basic math behind overclocking and how you might push your own system a little harder and faster. The goal here is to get better, stable performance for your money. After all, it doesn't matter how fast your computer runs if you have to wait for it to reboot from a crash every 10 minutes."