The Five Second Rule  (5-SR)

You’re at work, at school, the zoo, a jail, anywhere, eating something, enjoying your day, when suddenly your delicious meal slips out of your hands and falls onto the ground. What do you do?

History 

"Why five seconds? Because that’s how long it takes for germs to re-group and infect your food.” Actually, I figured that when you drop something, most of the dirt and germs scurry out of the way of being crushed, and then slowly return back to where they were, and that process takes exactly five seconds, hence, the five second rule. (I made that up.)

First of all, as soon as you drop whatever it is your eating, pick it back up. This makes life easier for all of us.

Now examine what you are eating? Is it cake? A cookie? A slice of pizza? Whatever it is (unless its soup) can somewhat be saved...

What to do?: A quick examination on what you can and cannot eat off the floor.

So, your order of tofu and bean sprouts just fell to the ground? Most of the time, I'd just play it off and pick it up real quick. I don't mind a little dirt if I can still have my tofu and bean sprouts.
But what if you drop if somewhere nasty? 

The surface type is a range of floor surface clean-ness. It's a range from 1-10.  Surfaces of "Ten" are considered to be "hospital Maternity Ward". And Surfaces of "one" are considered to be the equivalent of dropping it a port-o-let or dropping it on the floor of a McDonalds. Whether or not the surface is wet also plays a part in the degree of the Surface type. Other un-eatable locations include: 

• Any bus stop, or on the bus itself. (Bums and crack whores ride the bus too you know)
• Bathroom floor. (The only clean thing in a bathroom is the hand-dryer button)
• In a toilet. That ones a given.)
• Into the trash. (this has some questionability though.)
• If you drop it, and then step on it. (Yo feet is stank nasty sucka!)
• Subways or other mass transit vehicle.  (Dese places be mad stank nasty ma' brotha'!)

To better understand this we must also understand the many different constants that must be worked in. Food comes in all types. (i.e. Dry, Wet, liquid, solid, homogeneous / heterogeneous nature.) The constant is dependant on what sort of food you just dropped on the floor. Keep in mind this is a very loose measuring system.

Constant Level - Food Type

0 - Very Dry Solids (Potato chips, Vanilla Wafers, Crackers, Hard un-eaten Candies, Oreo’s and certain cookies)

1 - Semi Dry Solids (Whoppers, Chocolate Chip Cookies, Uneaten Caramel squares, Nuts, Some Un-refrigerated Fruit like Cherry's)

2 - Mid Range Foods (French Fries, Candy Bars, Buttered Toast, Bagels, poptarts)

3 - Semi Wet Food (Face Up Pizza ,Spaghetti, Piece of Steak, Sandwich, Hamburger, Vegetables, Apple slices, Half eaten Hotpockets)

4 - Sticky Foods (Damp Skittle, Recently Licked Lollipop, Gum, Face down Pizza)

5 - Near Liquid Foods (Slushie, Ice Cream, Stew and Soup Chunks)

10 - Gone-ner Category Liquids (Beer, Soda, Soups, Stew Broth)

Final Thoughts: what's left you ask?

All of the stuff that I've discussed are the most important part of the 5-SR, but I didn't include factors such as, where you are from. Let's say you're a neanderthal eating some mammoth tusk, and you drop it on your cave floor? Whatever, It's still good.

It's still good. That's what this whole thing is basically about. You don't want your food wasted, do you? So, next time you drop that slice of pizza, take time to assess the situation, weigh out the pros and cons, and then say to yourself, "Whatever, it's still good" and gobble down your slightly ruined slice. Farewell and enjoy.

Some information was gathered from epinions.com. Thanks to them for the help.