So, having grown up watching Power Rangers, I thought that having a little communicator on your wrist was pretty cool. As is with all our projects, this is a work-in progress. But, I have gotten to a place where I can share my progress.
The walkie talkie uses the nRF24L01 RF transceiver to transmit audio. Using a pretty nifty Arduino library, we can transmit and receive audio using a simple microphone circuit and speaker. Add in a little button to control which radio is talking and which one is listening and you have a walkie talkie. Questions, comments, and advice is always welcome. Enjoy!
Step-by-step instructions are on the project's Instructables page