A portable gateway device facilitating shared access to a proprietary wireless network. The portable gateway device acts as an external modem for one or more auxiliary personal computing devices, and the device includes: a local power supply, one or more processors, one or more memories, an identification module associated with a proprietary wireless network, a first wireless communications component, and a second wireless communications component having longer range communications capability than the first wireless communications component. The portable gateway device is configured to facilitate one or more external computing device accessing the proprietary wireless network by: establishing communications with a first external computing device using the first wireless communications component, authenticating access with the proprietary wireless network using the second wireless communications component, and subsequently relaying communications between the first external computing device and the proprietary wireless network using both the first and the second wireless communications components.