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.
Adding a Timed Button to a Project
This tutorial will walk you through making a timed power controller for interactive projects. You will learn how to add an on button that will provide power to your project for an amount of time and then turn off again.
Beefcake Relay Control Hookup Guide
This is a guide for assembling and basic use of the Beefcake Relay Control board
TSH82 Configurable OpAmp Hookup Guide
The TSH82 Configurable OpAmp board offers the designer a great balance of performance and flexibility. We'll show you how to get the very best out of your board!
Hookup Guide for the SparkFun RedBoard Artemis
Get started with the RedBoard Artemis - all the functionality of the SparkFun Artemis module wrapped in the familiar Uno R3 footprint