How long until the electricity fails?

[StainlessSteelCynic]

So okay, this article was written in response to a "What if the zombies attack?" question but the basic info is valid. Plus the writer has let their sense of humour out for a little bit of a play and that saves it from being a dry technical talk.
I thought this might prove interesting in light of past discussions about the general level of destruction from a world war let alone due to EMP problems.
Straight Dope article