On the technical side, this project is a bare-bones Arduino Walkie-Talkie. It's based around two way radio, and it uses the NRF24L01 Radio Module to transmit and receive information. The radio module should allow for communication up to 1km, provided there is nothing blocking the signal. The code runs off of the RF24Audio Library, which makes it a super simple program. Great for those not software inclined. ;) The whole project costs around 75$ to make, depending on where you get your parts, and it takes about 3 hours to build.