overclocking is great but can be costly and dangerous if a few things are not taken into consideration:

1) overclocking is really only useful if you run programs that could use every extra cycle possible in order to complete processor-intensive computations, like a distributed-computing project (SETI, Fold@HOME, etc.), rendering a large PDF file, compiling a *really* large program, or doing high-level math computations like solving the universe in one go.

2) running highend graphic games like FarCry, DOOM3, GTA:3, etc., get no benefit from overclocking because *that* processing is done on the graphics card, not your CPU.

3) in the case of AMD lately, you are probably already running a *production* overclocked 1.8GHz chip anyway, sold as a 2Ghz chip since that was the safest, stable level of speed that particular production line could handle.
and lastly, you probably won't see any increase in computational power because the extra heat now generated 'saps the strength' (so-to-speak) of the processor. you would need to get it down to pretty cold temperatures (at the very least below room temperature) so that the electrons being pushed around can take advantage of the overclocking. overclocking generates more heat which (in principle) wears out the processor if it is not properly cooled down to remove that extra heat (like a freon or liqued-nitrogen colling system). the fans and heat-sinks in a typical PC case ain't gonna work without some help.

so unless you are cooling the processor down, and using the PC regularly for things mentioned in point 1 above, overclocking probably does little more than shorten the lifespan of the processor for you.