It will take forever. In my whole career of Pokémon (which is like, 11 years long, or whenever Yellow was released here) I NEVER found a shiny naturally. I do own 2 but none I got myself.
1. Beedrill, got if as a gift from a girl
2. Ninetales, won it in some kind of forum contest on the Platinum trade board
I also got the red Gyarados.. but it's the red Gyarados.
--
http://www.youtube.com/watch?v=6Lo0qD6rOz8