Just to clarify, is there in fact battery pull and drain from BT, Wifi and GPS even if you are not actually using them as there no app running needing them and no icon showing them active in the menu bar? I am curious if they are sending out polling or searching signals and thus, still draw the battery down? It seem they must, agreed? Is it a substantial pull? I kind of want to leave them all on, but have started the habit of having them off and just using a widget to turn each on - 1 by 1 - as needed.. but that is kind of a PITA and I wonder if it is not even necessary?