From an extensive Fortune Android article (via Louis Gray via Buzz)
Today, of course, Android is impossible to ignore. It is the mobile operating system -- the brains of a cellphone -- that powers more than 100 million gadgets. (That number will be out of date by the time you read this: Every day another 400,000 Android devices are activated.) Apple's (AAPL) iPhone gets credit for showing consumers just how cool and powerful a mobile device could be, but Google democratized smartphones by making Android available free to any handset maker that wanted to use the platform. At last count, Android software was on more than 300 different phones and tablets around the world. The only smartphones that use the iPhone operating system? iPhones. "If you just plot the graph looking at how quickly we grew," says Rubin, now senior vice president of mobile at Google, "it's almost vertical."