Hi @ndarkness,
Interruption based programming of the UART interface will be the way to go when resources are scarce. This will enable low power nodes, but requires more knowledge and is tougher to program and debug. You can for instance make the MCU sleep until a message is received on the UART. Handle the message and sleep again. But this has nothing to do with this subject or forum post. Checkout the sleep modes for your MCU for more information.