Here’s an application note from Atmel on power saving techniques to reduce energy consumption (PDF!):
In this demonstration we will show you how to extend the battery life of our application by multiple factors by modifying only the firmware. You will see that while some of the modifications are very simple and only require setting some registers, other modifications will need some rewriting of the code.
We will use a capacitor as a battery in this demonstration because it is easy to recharge with the same amount of energy. We will use the discharge time as a measure of power consumption.
Always nice to know techniques. Really useful. I let microchip application note about low power design. I think you have post it earlier.
http://ww1.microchip.com/downloads/en/AppNotes/01416a.pdf (PDF!!)
Atmel also has a video on this:
http://www.youtube.com/watch?v=DGtYKFhLxPg
Be wary of anyone who talks about “low power processors” without talking about sleep modes and low power peripheral design. A good low power processor is one that provides you with peripherals that are flexible enough to allow you to spend as much time in the lowest power modes as possible. For most low power apps, the MIPS/uA rating is meaningless.