The science behind the "five-second rule"

We've all done it: dropped the something-delicious on the floor and wanted to pick it up to finish eating it (oreo cookies, anyone?). Most people I know (and 70% of all adults, according to the article) are familiar with the so-called "five-second rule." That is, you can eat the dropped food so long as you pick it up within 5 seconds. I've always viewed it as rationale for eating something that you're going to eat anyway, but here's an interesting NY Times piece that explores some scientific research behind the rule.

My take: if you're invoking the rule, I'm betting you're all right. Most of the time.

More difficult might be explaining why I, as a parent, sometimes allow my daughter to eat something she's dropped on the floor, while other times prohibiting it. I'm sure it appears completely irrational to her, and I can't fully explain the calculus used to make the determination myself. But, sometimes eating what we've dropped is all right, and other times, it's clearly not....