Check out Yun Shield – one of the most powerful shields for Arduino. The Yun Shield provides internet connectivity and storage solution for Arduino boards. It runs same system as Arduino Yun board – OpenWrt (Open source Linux) system. The Yun shield and Leonardo is effectively equal to Arduino Yun board. It’s fully compatible with Arduino IDE v1.5.4 or later and can work with Arduino boards – Uno,Duemilanove, Mega etc.
Supports internet connection via LAN port, WiFi or 3G dongle and USB flash to provide storage.Ideal for Arduino projects incorporating internet connections and storage.
Buy Yun Shield from Pakronics: