Hey Rands.. I have read a book which uses something very much like your INSPIRED PLOT. It's called _Girlfriend in a Coma_, by Douglas Coupland. It's a very good book IMO. The plot device is quite effective and I'm sure you could do as much with it as Coupland did. I doubt your story would end up being very similar to his, though (BUT NO SPOILERS).

BY THE WAY YOU AREN'T REALLY SUPPOSED TO KNOW THAT IT CHANGES IN THE MIDDLE SO REMEMBER TO ACT SURPRISED.