Yah, that's a cool theory! but it doesn't have to like a ghost or something posessing her, it could just be the "spirit of prophecy" or summat... y'know, like how in Delphi the oracle would chew laurel leaves and go into a trance and the god would speak through her... 'k, i like mythology way too much,

I wonder if Voldie could really access the prophecies if it was a posession thing... it might be like how he broke through Crouch's memory charm on Bertha Jorkins, but if another something was prophecying through Trelawney, I don't think VD could get ahold of any memory of the prophecies. Hmm...