Mobile phone penetration has been steadily increasing worldwide for many years, so much so in fact, that recent data suggests there will be more than 5 billion wireless subscriptions by the end of this year. Wow, that’s a ton of Razrs. Another interesting tid-bit—the average age an American receives his or her first cell phone is 8. There are many more wild details listed in this infographic from the Cell Phones Blog. Be sure to check out the section on SAR, or specific absorption rate.