Hey, why not pave the whole planet and give everyone one square meter (with a coffee can toilet)? Let's see, the Earth's radius is approximately 5000 km, that's 5x10^6 meters, so we have a surface area of (4 pi)R^2 or about 12 x (5 x 10^6)^2 = 3 x 10^14 square meters, so actually you could have a population of 300 trillion people...for a day or so.
You have gone so far stupid, I really shouldn't reply. BUT, with technolgy, we could build one hundred stories high, then each could have 100sq meters in which to live. Having a power source like in the Star Trek universe, we could all have enough for more than a couple days.