The Game of Ouija
Oujia boards are nowadays synonymous with contacting the dead, but it may surprise many people to learn that Ouija was actually a game designed, owned and licensed by Parker Brothers and was originally marketed as a tool for contacting people's inner wisdom, not the dead. During WWII, some people thought that Ouija boards could be used as a means of contacting living soldiers serving on the other side of the world. So where did we get this idea that Ouija boards are conduits to the spirit world? Thank Hollywood for that.
Ouija boards were as common place and innocent in many households up until the release of 'The Exorcist', which linked the use of Ouija boards with becoming a bile spitting, daemon possessed victim. People who formed their world views primarily on movie portrayals declared Ouija boards tools of the devil, and sales dropped dramatically. Nowadays you'd be hard pressed to find a Ouija board amongst the Barbie and Ken dolls in toy stores, not because there is any validity to the claim that you can talk to dead people with them, but because people would panic and remove their little darlings from any store that sold tools for chatting with dead people. Ironically, lead filled Hannah Montana products cause little to no alarm amongst the same demographic, which only goes to show that natural selection doesn't work fast enough.
Ouija boards may not be a good way to talk to the dead, but that doesn't mean that they can't be quite a lot of fun. If people insist that they can be used to contact the dead, there's no real reason to dissuade them from the notion. Superstition isn't only the bane of human existence, its also a potential source of plenty of amusement.
Certainly using one with friends is a good way to amuse each other as everyone will swear up and down that they are not deliberately moving the planchet (or 'shot glass') as we used to call it. A few friends, a flat surface, a small glass and a little bit of alcohol if you're of legal age is a recipe for a fun party in which you can legitimately call someone you don't like a fat skank and blame it on the spirits.
Even more amusing than the freedom to subtly manipulate those around you, are the tales that come out of Ouija board use long after the event. The human mind is incredibly susceptible to suggestion, and odds are that if people think there are spirits all around them, they will begin to report psychic phenomena like flashing lights, objects falling off of other objects (yesterday, the spoon falling off the bench would not have been cause for concern, the day after playing with a Ouija board it becomes a sure sign that you've managed to trap a ghost in your living room.)
Playing the Ouija board is fun because it is a game played not so much on the board, as in the minds of the players. There are few games like it in the world, which is why dismissing it as a tool of the devil is a rather senseless waste of a useful and interesting social diversion.