Yeah I just recently read "One Second After" by William Forstchen, and it was an eye opener to me. The book deals with the after effects of an EMP, and it REALLY hit home with me because the area he wrote about is where I grew up, and is not far from where I'm currently located. I know most if not all of the roads, locations, land features of which he speaks. It had a serious impact with me emotionally. Definitely a wake up call.
Like he speaks of in "The God Virus" the "Golden Hordes" will come a lookin for food, water, and whatever you have. You need to be able to make them move along.