Just received an Arduino Uno R3 with Vilros Ethernet Shield kit in the mail. Will be connecting it to the Pi soon. Not sure what to do with it yet. It will probably demonstrate Internet of Things (IoT). Check back to find out what it will do.
UPDATE (03-OCT-2014): Installed the Arduino Uno driver software for Windows 8.1. Plugged the Arduino Uno to my Acer netbook via USB. Inserted an LED into pin 13 (long leg) and ground pin (short leg) of the Uno. Downloaded the Arduino IDE (Integrated Development Environment) software. Started the IDE and opened, compiled and uploaded my first sketch (program). Got the LED to blink at 500 ms, 250 ms and 100 ms.
UPDATE (04-OCT-2014): Tried the TMP36 temperature sensor. Next is to get the temperature data to be accessible on the Web.
UPDATE (05-OCT-2014): Got the Arduino to publish the temperature on a web page.
UPDATE (15-DEC-2015): Used ThingSpeak to scrape the temperature data from the abovementioned webpage and to create a channel for publishing the collected data on the chart below.
