xkcd: Sky Color
December 10, 2012 at 10:21:58 AM GMT - permalink -

- http://xkcd.com/1145/

Vi Hart: Blog: Entry
October 1, 2012 at 11:13:20 AM GMT+1 - permalink -

- http://vihart.com/blog/mobius-story/

Online Python Tutor - Learn programming by visualizing code execution
September 23, 2012 at 5:38:38 PM GMT+1 - permalink -

- http://www.pythontutor.com/

xkcd: Potential
September 20, 2012 at 10:53:39 AM GMT+1 - permalink -

- http://xkcd.com/987/

xkcd: Airfoil
September 13, 2012 at 7:28:45 PM GMT+1 - permalink -

- http://xkcd.com/803/