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.
Battery Babysitter Hookup Guide
An introduction and getting started guide for the Battery Babysitter - a flexible LiPo battery charger and monitor.
MicroMod Ethernet Function Board - W5500 Hookup Guide
Add Ethernet and PoE capabilities to your MicroMod project using the Ethernet Function Board - W5500.