Actually, I don't feel that a pendulum and a ouija board are in the same class at all. The pendulum is, to my mind anyway, a tool for focusing your own abilities and sensativities. The ouija, as stated several times in this and other threads, is primarily a tool for contacting other entities outside yourself.
I've used ouija boards a few times with mixed results. Fortunately I've never had any terribly frightening experiences with one. Though one time a couple of friends of mine and I were using one (many, many years ago) and the letters seemed to spell out giberish... until someone pointed out that it appeared to be a foreign language. I'm sorry to say that what the message was is lost in the dusty archives of my mind, I seem to recall the language being French though. As far as any of us knew, none of us could speak French.
As for pendulums, I've used them a lot for many different purposes. I've used them for the usual yes/know/uncertain answers to questions. I've used them for finding placer gold deposits. I've used them for picking out which crystal, from several which attracted me, would be the "strongest" one for me. And, most recently, I used a pendulum to help me with picking out a quartz sphere for scrying.
Like Buzzbee, I have made my own pendulums, but I have also purchased them. I currently own three different ones; one is a Swarovski crystal on a chain, one is a rutilated quartz I wear around my neck, the third is one I made out of an shed elk antler (I also wear this with the rutilated quartz one). When I want to use either of the two I wear (wear them most of the time), I untie the cord I wear them on and clip them to a light chain I carry with me for this purpose. It works for me...