According to analytics firm Flurry, the adoption rate of iOS and Android devices has now surpassed all other consumer technologies in history. Smartphones and tablets are being adopted at a rate 10 times faster than PCs from the 1980s, two times faster than the Internet in the 1990s, and three times faster than the current social networking boom. Flurry’s latest estimates point to a combined total of more than 640 million iOS and Android devices in use during the month of July. The firm also found that 78% of U.S. adults aged 15 to 64 were using smart devices during that period. China is quickly catching up, however, growing a whopping 401% year-over-year. It is estimated that at the current rate, China could overtake the U.S. as early as the upcoming holiday season. Along with China, three other countries — Chile, Brazil and Argentina — all showed growth rates exceeding 200% in the last year, while four others — Vietnam, Mexico, Russia, Turkey and India — grew more than 100%.