The five second rule: The idea that if you drop food on the floor you can still eat it, provided you pick it up fast enough.
There's a study out of Birmingham, England on the topic. They tested toast, pasta, biscuits (the British kind), ham, dried fruit, and a sticky dessert, dropped on both smooth tiles and on carpeting for anywhere from 3 to 30 seconds.
Carpets leave less bacteria than tiles...and five seconds is basically alright.
Also, they found 87 percent said they would eat food that had fallen on the floor, with more than half of them women.