So the corollary, that Some PC owners also own a Mac is not true? The not-vice-versa part of the title doesn't make any sense. If I own a PC and a Mac, then I am BOTH a PC owner who has a Mac, and a Mac owner to owns a PC, or, to put it like the title states: "One Mac owner also owns a PC, AND vice-versa."

Oops. The URL is for some clock that uses a system in Europe. It's not GPS based, from the looks of the description.