OK - Standing in the space shuttle as it is crossing the Earth’s atmosphere.
That would put you one foot in a bound area called “Earth” (317 million sq. miles or so) and one foot in a little area marked on the maps as “The Milky Way” (510 trillion sq. miles give or take a few).
I contest the concept of “The Milky Way” being bounded. There is no agreed upon definition of all that comprises it, or what it’s bounds would be. In addition, Earth would likely be contained within the boundary. Much like saying you have one foot in Kansas and the other in the United States.
Nope. Earth is within the Milky Way, which is the name of our galaxy.
Much like all the various land masses / political boundaries we have been naming are all contained within the larger, bound and measurable area of the Earth’s atmosphere. The Milky Way has an estimated size and area, and is defined by name. You have to think outside the box on these important scientific questions of our time.
But I do concede there is no one foot in/one foot out so the result of the space shuttle theory would have to be either the entire size of Earth in her atmosphere, or the entire size of the Milky Way.
OK, first of all, I never think inside the box.
Second of all, the size of the galaxy is approximated, but not it’s boundaries. There’s nothing like a line that will determine whether you are in or out of the galaxy (that I know of).
But your Space Shuttle example is pretty good. There is the Kármán line which is the accepted boundary between the atmosphere and space. I think its around 60 mi. up. It’s not a geographic boundary because there no distinct line there, but like a state boundaries that are based on parallel instead of natural feature, there is a accepted and agreed upon boundary.
So I say if the Kármán line is accepted as a distinct boundary between the atmosphere and space, we can say that whatever constitutes the next measurable area outside of that boundary is freakin humongous.
One day science will (*may - this is more along the lines of what I meant by thinking ‘outside the box’) have defined that area exactly, and when they do, it will surely win this thread. 
If you’re looking at sub-divisions within a country, Canada’s Four Corners has the US version beat handily:
Arizona - 113,998 sq miles
Colorado - 104,094 sq miles
New Mexico - 121,589 sq miles
Utah - 84,899 sq miles
For a total of 424, 580 square miles.
Canada’s Four Corners is on the 60th parallel, where Manitoba, Saskatchewan, Nunavut and the Northwest Territories all meet:
Manitoba - 250, 734 sq miles
NWT - 519,734 sq miles
Nunavut - 808,190 sq miles
Saskatchewan - 251, 700 sq miles
For a total of 1,830,574 square miles.
(All areas taken from the respective Wiki articles.)
The physicists will have to come in to say if space has a bounded determinable volume (or area?). I think it is much bigger than ‘freakin humongous’, which could be applied to things on the Earth side of the Kármán line.
This line:
“It’s not a geographic boundary because there no distinct line there, but like a state boundaries that are based on parallel instead of natural feature, there is a accepted and agreed upon boundary.”
was supposed to read:
“It’s not a geographic boundary because there is no distinct line there, but like a state with a boundary that is based on a parallel instead of a natural feature, there is an accepted and agreed upon boundary.”
Are you saying that it could even be freakin A humongous? We’re going to have to get a ruling on that.
But for all intents and purposes the area of the Earth’s atmosphere is the current hand to beat. (and I keep my options open on the Milky Way pending further input from those more in the astronomical know)
Well I can’t identify it by name, but there’s probably an atmosphereless rock out there bigger than the Earth’s atmosphere, or maybe something like a boundary definition for the Sun (but you could only have one foot in and one out at night), but it looks like you won for boundaries where at least one side is on Earth.
If we are looking for the “largest bounded area”, and aggregating what is on both sides of whatever boundary we are straddling, then whatever is on both sides of the boundary must be a bounded area. I accept that the earth and its atmosphere is a bounded area, but “everything outside the earth and its atmosphere” is not.
Ok, then I call one foot on Earth, and one foot in the atmosphere.
What with being three-dimensional creatures and all, any time we are standing on the earth we are also in the atmosphere (except perhaps when standing on the sea bed). Furthermore everybody all the time is in the position, except when under water or in outer space.
The OP calls for a bounded area. not a bounded space. So I think we are looking at straddling the boundary of two or more adacent two-dimensional figures. I’ll stick with Russia and the high seas.
Just short of the Australian record in post #2. But the actual answer might be the junction of Sakha, Krasnoyarsk & Irkutsk.
http://upload.wikimedia.org/wikipedia/commons/8/86/Russian_Regions-EN.svg
But those are two differing kinds of bounded areas. That’s like saying Colorado and the Rocky Mountains. But I’ll go with your 2D definition and still claim win with the South Pole.
No, the high seas is not a geographical concept like the Rocky Mountains. It’s a legal concept to do with sovereignty and jurisdiction, just like the concept of state.