Last night I had a dream involving my brother getting sick, and usually when I have a dream like that he ends up getting sick, unless I end up telling someone before he gets the chance to. The last time this happened was about three or four weeks ago, when I was in England. I didn't tell anyone, and when I was talking to my mom a couple days after the dream (she stayed here in Virginia with my brother) she mentioned that he had gotten sick.
So yeah, here I am telling people about the dream, so that it wont come true. Weird superstition... however you spell it, but it seems to work.