How do you untangle a rope? When the knots are few and loose, it is very easy, and just about any way will work. But climbers are as obsessed with runtime optimization as algorithms researchers. I learned this summer that the fastest way is to shake it.
How do you uncoil your power cord as you set up your laptop for class? Last year I used to do it by quickly undoing the loops one by one. This year, inspired by my mountaineering vacation, I have realized that the fastest way is to shake it. It works! I am saving at least a couple of seconds of preparation time at every lecture.