This USB board converts a USB connection into a RS-232 5V serial connection. Use this for Arduino and related boards that do not have a built in USB chip. Based on FT232RL chip from FTDI.
This USB Cable converts from a USB connection to an RS-232 TTL connection. Use this cable for programming Arduino boards that do not have a built-in USB connection.
This Wiznet 811MJ Ethernet module makes embedding internet functionality into your project easy. Plugs into compatible Ethernet adapter shield or the iTelegraph kit.