Nathan made me bring our Wifi Geiger Counter to work on and show off. This turned into more of a hacking project than a fixing project. This years conference badge features an MSP430 and a Nordic nRF24L01+ radio. They could communicate with each other and a tracking network. After realizing the badges could be aware of other badges I came up with a plan! Now the Geiger Counter detects other HOPE badges!
[Via Rob T. Firefly]