When looking at items to either use or pack in your go bag or any other thing you do look for multiple purpose item For example it has been suggested that you pack a heavy mil thickness garbage bag. You can use it as a trash bag or Poncho to keep you drier, water collection (but i would still boil the water).
A good Multi tool and tarps, cans, Zip lock bags are a definate must and lest we forget ROPE, cause Charlie Bronson always had rope! However, this isnt holly would and in Prepper land we use Paracord, Oh my gosh the uses of paracord let me count the ways, Mmmmm, well maybe you should count the ways. let us know how you use Paracord.