Built-In Ramp for Truck

They make ramps to get your 4-wheeler in the back of your truck.  The thing is not every one with a truck has a 4-wheeler.  Everyone with a truck does however at some point in owning that truck have a need to roll something big and heavy into the bed.  Today's million dollar business idea is to create a ramp that folds or collapses into the tailgate or one you could pull out from under the truck.  I personally think the one under the truck would be a better idea.  You could make it longer and probably a little more heavy duty and if you lined it up right you could actually use it to make the undercarriage more aerodynamic thus increasing mpg.