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.
LilyPad Basics: Powering Your Project
Learn the options for powering your LilyPad projects, LiPo battery safety and care, and how to calculate and consider power constraints on your projects.
Nuclear Battery Assembly Guide
How to put together your BYOT (Bring Your Own Tritium) Nuclear Battery Kit!
Buck-Boost Hookup Guide
This tutorial shows you how to hook up and use the SparkFun Buck-Boost board.
Secure DIY Garage Door Opener
Did you know that most garage doors are at risk of a roll jam attack? Here we make a DIY garage door remote-control system that is much more secure than most commercial-ready products using the latest in ECC cryptography.