From an interview with some flight attendants:
What strange things do people leave behind in the cabin?
It's best not to go there.
Everything your imagination can drum up, we'll have found it.
Many years ago, I did an assignment for an airline. I was in the office of their head of security and needed to do a quick math calculation, but I didn't have my calculator (this was before iPhones). He asked me, "Do you prefer HP or Texas Instruments?" I answered and he handed me a device from a drawer in his desk.
"Do you have one of each?" I asked him. "No," he said, "not one." Then he pulled a box out of that drawer and showed me that it contained about a hundred calculators.
"I have at least one of every calculator, cell phone, PDA, and pager that's ever been made. If it can fit your pocket, it's been left on our planes." They do try to return them, he said, but if no one asks about a particular type of gizmo on a particular flight within some number of days, it just goes into a big pile where the employees take what they want. There are just too many of them to keep track of each one's origin for very long.
And here I thought I was a clever boy for realizing my dad left nickels underneath the couch cushions.