Permanent Markerus Erasius

This isn't e-learning, but chemical-based learning. We never called it c-learning, did we?

You know, last time I was in a lecture room and accidentally wrote with permanent marker on the white board, I shrank by a foot, apologised, threw the marker in the bin, and tried to carry on around the fresh graffiti. I needn't have been so upset, here's a wonderful undo spell:

Lifehacker : erase permanent marker