Actually one of my friends taught his kids to count starting from zero.
For a while, someone other than him (e.g. a teacher) would ask his kid 'How many X are there?' and the kid would proclaim loudly and proudly: "Zero!"
For a while, someone other than him (e.g. a teacher) would ask his kid 'How many X are there?' and the kid would proclaim loudly and proudly: "Zero!"
Edit: I actually disagree with this method (although it's hilariously awesome), because having an item is not the same as having zero items. It might be the zero-th item, but it is not zero items.