If you are not using the Ethernet port for backhaul connections, you can use the port for connections to your wired clients, like a printer or desktop PC. Even if your device is capable of both WiFi and Ethernet, plugging a normally static device into the free Ethernet port of a convenient nearby Wifi Pod will help free up more airtime for the WiFi connections of other wireless-only devices.
IMPORTANT - Any device connected to an Ethernet port will always be connected to the secure zone.