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.
LTC4150 Coulomb Counter Hookup Guide
A "Coulomb Counter" is like a gas gauge for your battery. Here's how to use it.
Beginner Parts Kit Identification Guide
The essential parts for beginning (or even experienced) hobbyists that gives you all of the basic through-hole components you will need to get started playing with embedded projects. We'll identify a few parts in the kit and provide a few basic circuits to get started!
Buck Regulator Hookup Guide
Get started with SparkFun's newest Buck Regulator Boards - the BabyBuck and the Buck!
smôl Power Board LiPo Hookup Guide
Small in size, small on current draw. It's a smôl world! This guide will get you up and running with the smôl Power Board LiPo.