Minecraft's world-stretching water slide
Minecraft's world is made entirely of cubes, which it lets you very quickly place and delete. But while a single block takes a second, building something as sprawling and enormous as jonnyabc's waterslide would have taken hours, even with the help of four other people. Video below.
If you want to slide along it yourself, you can download the world from the original forum thread.
Via the reason we get so little work done, reddit.com.