How many times have you needed money immediately in your life, and how much money have you needed for those incidents? Personally, I do not recall ever spending more than a hundred dollars without at least a day's warning. Then again, I don't own a car, which is a big cause for emergency spending - but really that ought to have it's own fund treated as self-insurance.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.