Sharpen my swords (yes, I have swords. XD), load the shotgun and gather my nearby friends and family to a relatively isolated location. Build a simple water purifier out of some sand and charcoal, cut down the surrounding trees about a foot or so above the ground to keep any cover outside to a minimum and use the wood to build a wall around the location.
I've thought about this too. I've also read the "Zombie Survival Guide." Never take on a group of more than ten or so people because they'll get sick of each other and they're hard to provide for. Resource management is key.
Incedentally, I have the same plans on the off chance WWIII happens or other such civil disturbances. XD