The GSM Shield also includes a Telefonica SIM card that includes a worldwide data tariff which can be used anywhere there is a cellular signal.

The Yun shield found on the Dragino website features a small SoC running OpenWrt, separated from the rest of the Arduino board with a serial connection.

Berlin, 24th August 2012.- In conjunction with Arduino, Telefónica is presenting a new version of the Arduino GSM/GPRS Shield project at the Campus Party in Berlin. The project added a GPRS/GSM ...

OMC's H19 fiber-optic shield has been adapted as a stackable add-on for the Arduino Uno. It’s designed to simplify the integration of fiber-optic data links into microprocessor-based platforms.