Wow this is not going how I hoped at all. No more random arguments. Please only post if you are adding to the list, or "disproving" a majority of the things I listed on the first page. There are other places on the forum for unrelated arguments about the devil and what not. Posting your belief’s one way or the other without evidence will only make you look like the morons you think the other side is.
As for the straight line thing, this is what I was trying to say:
Take a piece of paper, our flat earth, and mark two points: the South and North Pole, on opposite ends of the paper. Because these point now exist in 2D, rather than on a 3D globe, it is possible for an observer on our paper earth to be facing both points at the same time, which is not possible on a round earth, and is reflected by compasses.
Also, as TheEngineer pointed out, note that on a round earth model, an imaginary longitude line can be drawn through any point; connecting the poles and an observer. On our paper flat earth, if the observer moves East or West, this line is broken. Not possible. For an observer on earth, the poles are always in opposite directions. If our observer went far enough East, for example, he could be facing the North pole, and only need to make a 90° turn to face the South pole, rather than a 180° turn.