Scheduler Algorithm
This white paper describes a patent-pending power-save scheduling algorithm. The idea of this algorithm is to assign tolerances to timing events and, whenever the CPU wakes up out of sleep to handle a timer interrupt or any other interrupt, to service as many pending timer events as may fall within the tolerances for those events. Many timer events in consumer devices need not occur with high precision. For example, a peripheral device might be polled every second and a tolerance of plus/minus 0.25 seconds is easily accomodated. Therefore, it is possible to move the scheduled polling event up by as much as 0.25 seconds to avoid waking the CPU again. Each saved wakeup avoids not only the wasted on time, but the overhead involved in starting and stopping the CPU clock.
http://sites.google.com/site/edwardcraighyatt/projects/power-save-scheduler/powersave.pdf?attredirects=0

http://www.faqs.org/patents/app/20090307519

Tips for Optimizing Battery Life in Smartphones
This white paper has some tips for optimizing battery life in smartphones. This paper is rather informal and is a "brain dump" of knowledge I've acquired along the way. The paper covers hardware, software, testing, and debug.
http://sites.google.com/site/edwardcraighyatt/projects/power-save-scheduler/powertips.pdf?attredirects=0

References
These are a few links you might find useful.

• Stefanos Kaxiras, Margaret Martonosi, Computer Architecture Techniques for Power-Efficiency, Morgan & Claypoole, 2008.
• Jeff Sharkey, Coding for Life--Battery Life, That Is, Google I/O Video Presentation, 2009.
• MSDN, Battery Life Debugging, Microsoft, 2009.