Linux Overclocking

What utilities are good for overclocking under linux? I've searched but found none..... Can I not overclock under linux :( ?

Well normally you would overclock the CPU through your bios regardless of the OS you're using.
If you're talking GPUs then I know that if you have an Nvidia card you can add CoolBits to your xorg.conf.

Hmm... Thanks for replying. I should've been more specific though. I was looking for ATI cards and found nothing.... I need ATI =).

Get rovclock from here (http://www.hasw.net/linux/). I don't think you can control the fan speed with it, however.