I don’t know how many people reading this may know, but you can use Google as a calculator. Doing a search for “4 * pi” will in fact return a special “first result” that is the calculation. This is handy as it also does unit conversions like in order to convert 22 km to furlongs. There are some easter eggs though, and this is definitely the best: number of horns on a unicorn. Maybe it’s just me, but this is incredibly funny to me.
I’ve been playing with the very impressive WolframAlpha and wondered if they had done anything similar. Sure enough “number of horns on a unicorn” return the expected result. Even more amusingly, my second guess, number of horns on a horse shows that they really having some fun: