haha, it does look like they "drop" off at a certain point, but I think they'd slip if it was plexi-glass, weird though, you need to get a small rock going rather fast to skip it, a human being would have to be going extremely fast I would think...
Also, while carrying those papers, act like your confused or frustrated while pretending to look at them so as to avoid awkward eye contact while walking in the halls. That way you don't have to make the call whether someone will acknowledge your "hi" or not while walking by.