I had a dream once that two really tall buildings were falling on top of me, and I was trying to catch them. Some airplanes were circling above and I tried to knock them down, when I woke up I was standing on my older brother's bed and holding both walls in the corner of the room as if I was supporting them. The next day was 9/11... which really freaked me out.
I have appocalyptic dreams pretty often too, some of which I seemed to be the cause of. It was as if I was ending the world. Odd thing is, I enjoyed the rest of the dreams pretty well with no one around.