SetCPU 2.0.3 – Overclocks/Underclocks Your Android Phone
SetCPU is a powerfull app for root user that allows to manage CPU usage. Combined with custom profiles, SetCPU can help you manage your CPU settings to optimize performance and battery life. It will work with most if not all rooted Android 1.5/1.6/2.0/2.1/2.2 builds on supported devices.
Warning: Very low or higher than normal frequencies may freeze your phone. Especially high frequencies (such as those enabled in certain custom kernels) have a risk of shortening the life of your phone. If your phone freezes, just yank out the battery.