SetCPU!

3C Toolbox is the comprehensive toolbox to save battery, tweak, tune, backup, secure and monitor any Android devices running any ROMs, any kernels.

No-frills CPU Control is a tool you can use on your rooted device to quickly set the CPU frequencies and governor to use.It allows you to use the highest frequency your phone supports and gain some precious FPS in your preferred game, or go down to the lowest frequency and gain some more juice when your phone is sitting idle.

CPU tuner gives you control over the power consumption of your Android device. Its prime purpose is to save as much battery as possible, but it can be used to overclock at the same time (if the kernel of your device supports it).

Droid Overclock allows full customization of CPU frequencies and adds a ton of extras to your rooted experience. You can overclock to increase speeds or underclock to save battery life. Set custom profiles to increase performance to the max.

A modified Kernel Adiutor (Kernel Tweaking App)

A small simple app to tweak a rooted Nook Color running the Cyanogen Mod 7, or Dalingrin's OC kernel.