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.
Powering LilyPad LED Projects
Learn how to calculate how many LEDs your LilyPad project can power and how long it will last.
Blynk Board Project Guide
A series of Blynk projects you can set up on the Blynk Board without ever re-programming it.
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.