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.
Electric Power
An overview of electric power, the rate of energy transfer. We'll talk definition of power, watts, equations, and power ratings. 1.21 gigawatts of tutorial fun!
PicoBuck Hookup Guide v12
The PicoBuck board is a high-efficiency three-channel constant-current LED driver.
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.
Getting Started with the MyoWare® 2.0 Muscle Sensor Ecosystem
The MyoWare® 2.0 Muscle Sensor, an Arduino-compatible, all-in-one electromyography (EMG) sensor from Advancer Technologies. In this tutorial, we will go over the features and related shields to connect the sensor to a muscle group.