Maker Jan-Piet Mens has fashioned a rather useful network monitoring device using an Arduino Duemilanove, Arduino Ethernet Shield and S65 shield. Since the Naguino is stacked together the device does not require soldering. Messages are sent over HTTP POST and include service state and a 21 character color-coded message. You can use the rotary encoder on the S65 shield to page the messages up and down as the display fills up. Full source code and instructions on how to configure Nagios are included.
Naguino: an Arduino-based LCD monitor for Nagios and Incinga