I had one back when I was a teenager. My friends and I used it quite a bit...took it to graveyards, deserted houses, all sorts of places. It was fun and interesting, especially when someone who wasn't playing with it asked a question none of us knew the answer to and the board got it right.
Then, I had one scary experience where the pointer went all crazy, then started spelling out threats. I haven't messed with one since.
I don't know if I really believe a spirit can talk to you through those things, though. It could have just been our subconscious the whole time.