Every site should have an implementation of the Konami Code. It makes things more fun!
If you're unfamiliar with it, the Konami Code is a "cheat code" that appeared in many of Konami's video games going all the way back to 1986. It was typically entered on a Nintendo controller, which looked like this:
Now it's often used on websites to reveal easter eggs to visitors when the code is "unlocked."
Konami JS includes support for gestures on smartphones, tablets and other touch-capable devices. Technically the code becomes "up, up, down, down, left, right, left, right, tap, tap," on these devices but... it's close enough!