[Tutor] Null Object Design Pattern Question

[Tim Johnson]

I have been looking at 

http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/68205

which has an example of using a Null() object.

Unfortunately, I'm having a problem wrapping my brain around
the usefulness of this object compared to just using None.

Does anyone have some further examples of the 'superiority'
of this approach over *None*.

Or pointers to further documentations.

Thanks
tim

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Tim Johnson <tim at johnsons-web.com>
      http://www.alaska-internet-solutions.com