I have this name, and I've never met anyone with the same name, nevermind the same spelling. There are a lot of different ways to spell it, but I'm rather biased to this way ("Caterina"). I personally love it a lot as a name--it always draws attention and remarks, sounds fairly melodic, and is obviously very unique. Don't give it as a name, however, if the idea of people mispronouncing it bothers you; in my case, only a very few people have pronounced it correctly the first time.
Caterina Medici, aka Catherine de Medici, is a famous bearer of this name. She was the daughter of Lorenzo Medici and Madeleine de la Toure d'Auverne, originally named Caterina Maria Romola di Lorenzo de Medici. When she went to marry Henry II of France, then only Dauphin, at the age of fourteen, "Caterina" was Gallicized to "Catherine", and she was known for the rest of her life as Catherine de Medicis. When Henry died in 1559, and Catherine's three sons, Francis, Charles, and Henry, each took the throne in turn, in all three cases, it was Catherine who held the real power.