posted 2011-04-09 at 00:41:
I just uploaded the first of many (hopefully!) embedded programming tutorials, a HOWTO for using a timer and interrupts to achieve low-power timings on an MSP430. This example uses either the internal low-power low-frequency oscillator or an external watch crystal to flash an LED one second on, one second off.
While this tutorial uses the MSP430 platform and the code examples are specific to the MSP430, the idea is powerful and has broad application. Modern microcontrollers are capable of significant power savings if the programmer can let them sleep when they're not doing useful work. You will notice a theme of interrupt-driven operation and no-op main loops in the examples on this site.