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.
Alternating Current (AC) vs. Direct Current (DC)
Learn the differences between AC and DC, the history, different ways to generate AC and DC, and examples of applications.
Photon Battery Shield Hookup Guide
The Photon Battery Shield has everything your Photon needs to run off, charge, and monitor a LiPo battery. Read through this hookup guide to get started using it.
Powering LilyPad LED Projects
Learn how to calculate how many LEDs your LilyPad project can power and how long it will last.
How to Build a Remote Kill Switch
Learn how to build a wireless controller to kill power when things go... sentient.