Porch Pirates are evil people who steal unattended packages from your front door. I believe I have devised a way to thwart them. Basically this system turns the front door into a mailbox of sorts. See it in action after the jump.
I wanted something that was simple to use, secured the packages AND the home, did not compromise weather sealing, was not too obtrusive, and could theoretically be added to any home.
There are protrusions on both sides of the door, and inside this space there is a drawer. The bottom of the drawer turns into a slide for packages when the drawer is closed (the red thing).
The drawer bottom/slide is weighted so it will pull the drawer fully-closed if the delivery person doesn’t fully close the drawer.
There is a magnetic weather seal on the front of the drawer opening that works like a fridge door, to help with weather insulation. The drawback is it takes a bit of a yank to open.
This system shouldn’t get in the way of opening or closing the door, and could even be bigger to allow for larger packages. I just felt this mockup was an ideal size for functionality and to prevent a thief from trying to unlock the door.
Dave's Geeky Ideas 
I’d say that, toss in a spring to the red flap? Have it close when not weighed down by a package, and it’d be really good. Have the flap be physically blocked from going down unless it’s closed, then gets reclosed when the package drops out.
That could be added, but some packages are very light weight. It might be unsightly to always have the ramp down but it’s a simple mechanism that should be easy to use/maintain.