I am recently retired from the Department of Electrical and Computer Engineering at Queen's University, Kingston, Ontario, Canada. I used the Arduino platform for a second-year robotics course I created in which student teams configure and program robots to compete in a year-end knock-out competition. The bots have to navigate a playing court to a number of randomly-selected ball pick-up locations (tagged with ID-transmitting infrared beacons), grab the ball, drive to the goal to drop it in and score, and do this as many times as possible in sixty seconds.
As part of their learning resources, I had developed a graphical simulator that allowed my students to test their robot code at home without the need for the actual robot or court. This was a natural extension of my earlier experience with creating a simulator for the Lego Bots I had introduced to our Queen's Engineering common-first-year programming course, and earlier microprocessor simulators I had also created (all of our labs use Windows machines). Since retiring, I have wanted to provide Arduino enthusiasts and other students a more generic simulation platform that was not targetted to any one specific hardware configuration -- UnoArduSim.exe for Windows is the result, and I hope you find it useful!
You can FIND ME on the Professional Engineers Ontario web site if you would like some degree of reassurance about the safety of my posted zip files (go to http://forum.peo.on.ca/cgi-bin/EPIM_Search/EPIM_Form_Search.do and enter Last Name: Simmons, First name: Stan, and check the security box, then click Search, and click on me and open and read my profile!) -- OR VIEW MY SCREEN PRINT OF THAT SEARCH PAGE RESULT BELOW (click on PDF below))