This is the worst advice EVER if your goal is to stay on task and increase your word count.
If you're looking for a study-breaker, a good laugh, or a reason to feel better about your own mistakes, though, this is a must.
On the NaNoWriMo forums, there is a magical place. A magical place reserved for all the typos, all the mixed metaphors and nonsensical thoughts that occur when you write a great volume of words at high speed.
This magical land of wonder can be found here, in the NaNoisms thread.
But first, a touch of good advice: put put down the coffee. I wouldn't want you to ruin your keyboard.