Wow, all of you have some pretty interesting accounts.
None of the stuff I've seen is TOO big but I guess I'll recap some of it anyway for fun.
Well, to start off, when I was a LOT younger, there were a few times I'd find myself waking up in the early morning hours to random voices calling my name.
Another time, I forget how old I was, but I woke up in the middle of the night to that humming noise of a firetruck/large truck coming from outside my room. Along with it was an eerie, yet faint orange/red glow in the hallway. It was a little brighter than the night light in the bathroom, so the light from it was shining through my doorway so I could see a bit of it on the wall. By this time I had turned my head away from the door, my head under the covers only peeking out. (the whole thing just REALLY creeped me out for some reason) To top it all of, moments later it seemed as if something was standing in my door, blocking most of the light and I just had that feeling like there was some kind of presence.
Other odd situations relate to this little path we found in the woods. There are tiny old cabins surrounding the path, and we've gone into the only accessible one quite a few times. The first time we really explored it, we all heard this loud animal-ish noise that sent us running. Another odd experience we had there was when my sister, a friend, and I were going to explore the other area of woods next to the path. When we got there, we realized getting into the area would be kind of difficult, so right before we were about to leave, my friend's cats ears perked up and a few seconds later we heard a quiet voice saying "Help me!". We were outtt of there right then.
Not too much else that I can think of... besides the little side room in the boiler room at this abandoned school. It wasn't really too scary, just odd how nothing was in the room besides a fire extinguisher, standing upright in the direct center of the room.
Gosh, I kinda wish I had experiences to talk about that were as good as all of yours. I'm really into the whole ghost thing, and I have been for a long time. Thinking about that abandoned school again makes me want to find a way in sooooo bad. >_<