Meet the WarSting: a sword that detects unsecured networks and glows. When you slash the sword, Sting will join the network and publish a message. To make your own, you are going to need a sting sword and a Spark Core. You get lights and sound. For instance, when you slash the sword, the toy makes slashing sounds. The below video shows this sword in action:
You can find out more useful instructions on Spark.io.