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.
How to Build a Remote Kill Switch
Learn how to build a wireless controller to kill power when things go... sentient.
Fuse Breakout Board Hookup Guide
Protect your project by adding a fuse in your circuit to save it from molten destruction.
SparkFun RTK Express Hookup Guide
Learn how to use the enclosed RTK Express product to achieve millimeter level geospatial coordinates.
Single Cell LiPo Battery Care
This tutorial will go over how to safely charge, connect, disconnect, reinforcing the cables, and handle single cell LiPo batteries.