[CEATEC 2010] Tagged World is showing a simple RFID application that could be used to retrofit entire natural gas infrastructures (ca$h-ing) to improve their safety/efficiency. By replacing existing valves with an RFID-enabled one, maintenance workers can inspect valves and notify the central office over a web application (demonstrated on an iPad to look cool here). The valve basically knows if it is closed or open via a simple mechanism. With an even simpler contact switch, the RFID then sends a “close” or “open” signal. The RFID data also contains things like the Valve ID, which can lead to its location data. The idea behind using RFID is that there are no power source that can lead to a spark (batteries, wires…). Instead, the reader sends a microwave to request for the RFID tag state. The residual power from that request is sufficient to be used as energy to transmit the data back. That’s the magic of RFID…