Google's free Wi-Fi network transports nearly 600GB a day

Google's muni Wi-Fi network in Mountain View, Calif., reached its third anniversary this month, and now transports close to 600 gigabytes of user data on a daily basis.
That’s double the volume from two years ago, says Wi-Fi vendor Tropos, indicating that it is one of the most heavily used open networks in the world.  
“We continue to experience extremely high demand – both in terms of users and bandwidth,” said Google’s Karl Garcia, who leads the Google Wi-Fi project.
“We've seen the iPhone and other Wi-Fi enabled handheld devices as significant drivers of the high demand we see. Currently nearly a quarter of all devices that connect to our network are handhelds, compared to almost none when we launched the network,” said Garcia.
The statistics are similar to what Wi-Fi network owners are saying across the country. Wi-Fi enabled smartphones are driving up usage. 
Last month, AT&T said it handled nearly 15 million Wi-Fi connections on its network, a 41% increase over the first quarter. The service provider said 49% of the total connections were made by integrated devices. This is an increase of 41% over the first quarter 2009--a significant shift that tracks with the growth of Wi-Fi enabled devices, AT&T said.
The network covers about 12 square miles and includes business and residential areas. The service is free. Google recently told FierceBroadbandWireless that it has no plans to expand Wi-Fi to other cities. AT&T and Cablevision offer Wi-Fi for free as a way to gain and retain customers on their fixed broadband services.