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 Power a Project
A tutorial to help figure out the power requirements of your project.
Benchtop Power Board Kit Hookup Guide
Need more power? This Benchtop ATX Power Supply Kit should help give you the boost you need to power those energy hungry projects.
Beefcake Relay Control Hookup Guide
This is a guide for assembling and basic use of the Beefcake Relay Control board
LuMini Ring Hookup Guide
The LuMini Rings (APA102-2020) are the highest resolution LED rings available.