Google (GOOG) announced that it will spend $3.2 billion for Nest, a Silicon Valley company founded by former Apple employees to develop better versions of common devices for homes.  The Nest acquisition gives Google a foothold in one arena of the “Internet of Things,” the growing phenomenon of connecting ordinary items to the Internet.   Silicon Valley tech giants are laser-focused on the opportunity for growth in the field, with Cisco (CSCO) CEO John Chambers saying at CES this month that it represents a $19 trillion opportunity.

“This will be potentially the biggest business opportunity in the history of people,” Janusz Bryzek, a vice president at San Jose-based Fairchild Semiconductor, told the Mercury News about the Internet of Things last month. “We are changing the Earth.”

“Google will help us fully realize our vision of the conscious home and allow us to change the world faster than we ever could if we continued to go it alone,” Nest CEO Fadell said in a blog post. “We’ve had great momentum, but this is a rocket ship.”  Nest will continue to operate as a stand-alone company with Fadell at the helm, Google announced Monday, with the deal expected to close in the next few months.

Nest makes Internet-connected devices for the home such as thermostats and smoke alarms. It has a host of products planned to make your home more “conscious” by connecting it to the Internet.  Google says it will abide by Nest’s privacy policy, which limits how customer information can be used.  Google does not have a good track record on privacy.  Hold your breath …