The West Coast city has 66 percent of its residents connected to the Internet from home computers, Web measuring company Nielsen/NetRatings found.
Six months ago, a majority of residents in just five cities--San Francisco, Seattle, San Diego, Portland, Ore., and Washington, D.C.--were connected to the Internet. In this latest study, completed in September, that figure jumped to 21 cities.
"The industry is still maturing," NetRatings analyst Peggy O'Neill said. "If the Internet becomes like our television sets or telephones, then eventually there will be close to 100 percent use in all cities."
NetRatings analysts also noted a spike in the number of Internet users who live on the East Coast, narrowing a gap with the wired West.
Many of the cities tracked this time around didn't even appear on the radar for the last report, O'Neill said. Kansas City, Mo., for example, ranked the eighth-most-wired U.S. city in September, but it didn't make the Top 35 list in March.
Of the cities that were tracked both times, New York showed the greatest surge in Net users. Half of the city's residents are now connected to the Internet, compared with 41 percent six months ago.
"U.S. markets have developed beyond the Western high-technology region, and there is less of a digital divide between the West Coast and the rest of the United States," Allen Weiner, vice president of analytical services for NetRatings, said in a statement. "Low-cost computers and other plug-and-play Internet appliances have contributed to the significant rise in home Internet access for wired cities across the country."
The Nielsen/NetRatings report also ranked the most-visited Web sites and top advertisers online during September.
America Online Web sites, Yahoo and the Microsoft Network (MSN) were the top three most-visited sites. About 64 million new visitors stopped at AOL, each spending about 41 minutes clicking through the pages. Yahoo hosted about 58 million new people who spent about an hour and a half at the site. MSN had about 48 million visitors, with each spending a little more than an hour using the services.
Truste, an advocacy organization that runs a privacy seal-of-approval program for retail Web sites, had the most banner ads with 2.5 billion impressions reaching 38 percent of all Internet users. Following were Microsoft, with 1.9 billion impressions, and eBay, with 73 million impressions.