This was one of the most fun hackathons I participated in. Built a line-busting robot using an ER-1, a Microsoft Kinect, and a Clover Mobile POS terminal. The robot would detect a line of people and then drive up to them offering them the option to do a self-checkout at the robot. The robot was using ROS, and perception was being done using PCL using the Kinect through an OpenNI driver.

The hard part was building everything in a day. Cool thing was that it generally did what I was hoping it would.

Here's a picture of Bernard scanning items to be purchased on the self-checkout app (which my colleage Jacob was able to put together the same day).