I forgot to mention that before we assembled the Printrbot Jr, I had received and assembled a Raspberry Pi for the Printrbot. Here is a picture of it:
Raspberry Pi is an open source board that runs Linux. The board costs about $35 which is dirt cheap for a fully functional computer. It has two USB ports, LAN port, HDMI port, VGA port, Audio Port, SD Card slot, and a couple of ribbon connectors. One of the ribbon connectors is used to connect to a web cam show at the top of the picture.
After building the tower, I loaded an Octoprint image onto the sd card. Octoprint is a Linux based web server that allows you to control your printer and view the webcam. This allows me to remotely control (especially with a wireless usb adapter) the printer AND to view what it is doing currently. So instead of jumping up every five minutes from where-ever I am in the house to check on a print, I can simply carry around a tablet or iPad and check what the printer is doing. This is really very cool.