Worldwide mobile phone subscriptions will reach five billion this month, equaling 73.4% of Earth's population according to data outfit iSuppli. Obviously some people hold several accounts and handsets so each "subscription" doesn't represent a person, but it's a remarkable milestone nonetheless. "If the importance of an event can be measured by the number of people it affects, then the proliferation of wireless communications stands out as one of the most significant phenomena in the history of technology," the firm said.

After surpassing the five billion mark, another 100 million will sign up for mobile services by the end of 2010, at which point the installed base of wireless handsets will reach 4.9 billion. Africa and the Middle East have the lowest penetration at about 50%. Meanwhile, cell phone subscriptions outnumber people in Western Europe, with a penetration of 157%. Many Europeans have several cheap subscriptions for coverage when traveling to other countries. Around 766 million Indians will pay for wireless services by the end of 2010.