Yes, Ram at speeds over 3200 are ment for overclocking.
Overclocking is rather fun, and a great way to get more performace out of your PC parts for free.
Many chips can OC well beyond the next chip up from them, for a fraction of the cost.
Ex. and X2 3800+ can rach 4200+ and beyond with ease. So you end up saving money there.
Some chips like the opty 144 go very far like up to 2.8-3.0 on air. which is like freakin awesome.