A couple seasons back, my friend lost his cell phone at some point and we didn't realize it until we were outside the park in the parking lot. But, we called it and a PKI security guard that had found it answered it and brought it out for us.
Also, way back when I still wore glasses, I gave them to my dad to hold onto while we rode The Beast. He put them in his pocket and somehow during the ride they made their way out of his pocket and into the bottom of my seat so I was sitting on them at the end.
Here's an interesting story from Cedar Point related to this topic.
http://www.sanduskyregister.com/articles/2...news/106556.txt