Oh Yes, how stupid of me, OK then we will put them all in Texas, no in fact I will be generous and we will put them all within the borders of the USA. Or do you feel that wouldn't be enough land and water to support them?
I am sorry I did not take you through the nearly impossible to miss implications. If you would put them All in the USA there would be 2827 people per square mile. To put that into perspective New York city totals 327 Square Miles with a population of 8,008,278(2000 census) that is over 24,490 people per square mile.
And before you miss the implications of the above. That gives you Canada and South America plus the entire rest of the world to grow food in, or obtain drinking water etc. As anyone can plainly see the Earth is huge and we as a species don't even make a dent in overwhelming the land mass or overburdening the water supply.
However we do have yahoos in charge who would like you to think such. What in truth is really happening is that we allow junk-science and downright lies to dictate policy which gives idjits like Al Gore the power to lead us all by the nose holding hostage our wallets and our liberty all in the name of keeping him in power.
Do yourself a favor and educate those around you how far wrong these suck-monkeys are before they drain us all of our freedoms.
There are already places in the U.S. that have restricted new construction because of the limited availability of water, as in southern Colorado, parts of Arizona, and in California. Oregon and Washington are looking at similiar challenges because agriculture and fisheries need water. This has nothing to do with available land but the amount of rainfall. In our southwest, many aquifers are dangerously low due to drawdown in excess of the ability of rainfall and ground seepage to replenish the aquifer. This is not junk science; it is real and happening now.
Desalination? Sure. But the first thing that will disappear in overcrowding are our freedoms. It is already happening in our cities, the most densly populated areas.