[LPDad]

Hey fluff, Over clocking simply means running you processor faster than it is "rated".
this is usually done by changing/adjusting something called the FSB (FrontSideBus). You can also overclock by changing another setting that the processor chip uses called the multiplier. (Usually if you want to increase the multiplier past the RATED limit of the chip you need to do a little creative work on the chip itself--usually by connecting 2 very tiny metal "dots" on the chip)
The FSB and the Multiplier can usually be changed in the BIOS (some motherboards--Like ABIT, make it very easy--you just open the bios and change a number or numbers. In most other motherboards you physically change little switches located on the motherboard itself.

When you overclock to any great extent (more than 10%) you need to increase the voltage that goes to your processor to get it to do more "work". As the chip does more "work" it gives off heat. More work= more heat (running the processor at a faster Speed= the Processor gets hotter and needs to disapate the extra heat--or else it gets too hot and stops working.)

By using different methods to cool the processor and remove the excess heat you can run the chip faster and faster (as long as you are able to remove the heat and keep it cool)

In this little story they were using liquid nitrogen, which is VERY COLD and can keep the chip very cool--> so they can run the processor at a higher speed.

Thats it, without getting too technical.
Hope it helps you understand.

I Actually have an AthlonXP 1800 chip, which I slightly overclock so that I end up with it running at the equivilent speed of an AthlonXP 2000.