So China will have the largest number of mobile users in the world soon. If they don't already.....
Europe has historically led the world in mobile penetration. Part of this is related to a history of POOR landline, where the countries use different wiring in homes (copper in U.S.) but aluminum and other lines have been used in Europe. Additionally, you have to remember that Europe's infrastructure is MUCH older (historic buildings cost a TON to retrofit so many never did) & they had TWO world wars on their turf, where much of the infrastructure was blown apart and never rebuild completely.
Getting back to the point.....
The U.S. is about to become the largest phone browsing nation in the world....Interesting little factoid. All we need now is to enable payments via cell phones (Like Japan/Europe) and we will exit the cell phone "dark ages."