Reducing Arduino Power Consumption
Contributors:
Alex the Giant
Alex the Giant 
Resources and Going Further
More information on low-power modes and options can be found in the datasheet for the 328P.
For more power-related fun, check out the following SparkFun tutorials.
Hobby Servo Tutorial
Servos are motors that allow you to accurately control the rotation of the output shaft, opening up all kinds of possibilities for robotics and other projects.
How to Build a Remote Kill Switch
Learn how to build a wireless controller to kill power when things go... sentient.
Hookup Guide for the SparkFun RedBoard Artemis ATP
Get started with the RedBoard Artemis ATP - all the functionality of the SparkFun Artemis module wrapped in the Mega Arduino Footprint
Fuse Breakout Board Hookup Guide
Protect your project by adding a fuse in your circuit to save it from molten destruction.