CUPERTINO, CA — It may not be Apple chairman Steve Jobs’ favorite indication of the popularity of his company’s ubiquitous communication device, but over the past year Google Trends has reported a sharp increase in the Web buzz associated with the term “iPhone porn.”That really doesn’t surprise adult industry insiders. Vivid reported that 50-percent of its mobile traffic is iPhone-based, and Chief Executive Officer Steven Hirsch said he expects that percentage to climb with the July 11 release of “iPhone 2.0.” To take advantage of the new model’s increased ability to interact with next-generation Web features, Vivid is investing hundreds of thousands of dollars in a new “supersite” it plans to launch this summer, Hirsch told Time.

Pink Visual also plans to launch a 3G iPhone portal this summer, according to spokeswoman Kate Sylvan, who added that the company’s current iPhone-compatible site attracts 3,000 visitors daily. She said many people who travel for business prefer to access porn on their iPhones instead of on company-issue laptops or public computers.

Penthouse Media Group and Digital Playground also have projects in the works to take advantage of the iPhone’s popularity and the increased functionality of the new version. Penthouse is investing tens of millions in research and development in creating interactive FriendFinder interfaces, Chief Executive Officer Marc Bell told Time. Digital Playground is launching a new portal that will automatically adjust to the iPhone’s browser. Founder Ali Joone expects the move to give a significant bump to the $50 million Digital Playground annually earns in mobile revenues.

“In your palm, the iPhone is more cinematic than other devices,” he told Time.

Adult entertainment companies are finding the iPhone may be the key to mobile distribution of adult content. Europeans were early adopters of the distribution platform, actively consuming interactive video-chat with adult models, text services and still images. However, until the iPhone demonstrated how good video could look on a small screen, there wasn’t much call for any kind of mobile porn in the U.S. That may be about to change. The one remaining hurdle to widespread adoption is speed, but iPhone 2.0 promises to leap that obstacle. The new version is reported to be nearly twice as fast as its predecessor at loading pages and more than twice as fast at loading video.

Of course, Apple doesn’t condone the distribution of porn to the iPhone, but spokeswoman Jennifer Bowcock acknowledged the gadget just might be the catalyst that gets people thinking seriously about mobile porn.

According to Nielsen Mobile, about one third of iPhone owners watch video on their phones, nearly 10 times the number who watch video on other mobile phone handsets. In addition, three out of four iPhone users are adult males with significant disposable income, and iPhone users say they spend money on entertainment: Three quarters of them spend more than $100 monthly on connection and data charges. Only one-fifth of users of other handsets spend as much.

The porn police already are gearing up for a fight, however, and Apple is planning to head off their objections at the pass. According to Bowcock, iPhone 2.0 will include parental controls.