A man by the name of "Groobotube" is about to simultaneously blow your mind, give you a migraine, and impregnate you with his unbelievable speedrun of Portal. He ends up finishing the game in an unparalleled 18:05, which is far better than what 99.9% of us could ever dream of accomplishing.
In all honesty, it's pretty difficult to make out exactly what's going on in this speedrun, especially during the later levels -- but it sure does look cool. It even had me yelling "oh hell naw" in disbelief on more than one occasion.
If you've been yearning to pick up on some of the more advanced maneuvers, you won't want to miss the second half of the run, which can be viewed after the break.