The wireless network covers some 90 per cent of the Silicon Valley city of 72,000 and offers maximum data-transfer speeds of up to 1 megabit per second - slightly slower than DSL.
The system cost about 1 million dollars to build and uses 380 transceivers mounted on street-lights throughout the 31-square- kilometre city. Initial reviews of the network indicate that it works smoothly in open areas but that connections can be patchy in enclosed spaces.
Analysts have speculated that the online advertising giant set up the network as its prototype for launching a national wi-fi system covering the entire US.
But Chris Sacca, Google's head of special initiatives, said the main purpose of his company's backing local wi-fi access is to clear the way for broadband entrepreneurs and overcome legal roadblocks by established telephone and cable TV providers.
"We want to inspire these networks to be built. We want to throw our hat in the ring and show the promise of these broadband networks," Sacca told the San Jose Mercury News. "We wanted to make it very unpopular for anyone to oppose the promise of these networks."
Ellis Berns, economic development manager for Mountain View and the city's liaison with the company, added: "It's really providing them an opportunity to better understand how people are accessing this technology and how this technology works."