No one outside Apple knows what it looks like or any of its newest features. But news that a fourth-generation iPhone may already be in use fueled a buzz Monday on when the must-have device will debut.

MacRumors, a blog that follows Apple products, broke the story Monday that Pandav, an application developer, has monitored usage by an iPhone 3,1 -- a moniker unused by any previous models of the combination iPod and smartphone.

The current version of the iPhone, 3GS, which has a faster processor, was identified as iPhone 2,1 on application-usage analytics several months before its launch, according to the MacObserver.

Ready for Verizon?

Pandav spotted the new ID on iBART, a guide to the Bay Area Rapid Transit system in northern California. The first analytics sightings of the last iPhone were also in the San Francisco Bay area. Apple is based in Cupertino, a San Francisco suburb.

Judging from past experience, that could mean the new iPhone might be released in about eight months -- the period between the last field test and launch.

News of the new phone comes just weeks after another report that the next iPhone will be compatible with carriers around the world and, unlike current models, with Verizon Wireless in the United States. AppleInsider, citing a report by OTR Global, reported that the iPhone could be available in the third quarter next year and contain a hybrid chip made by Qualcomm and a 2.8-inch screen that is smaller than the current 3.5-inch display.

Verizon compatibility would be an "enormous" game-changer for the iPhone, according to Mordy Hackel, president of KJ Technology, a New York-based services provider for upscale residential clients and small to midsize businesses. "Among people that I speak to who love the iPhone, what they hate most are its problems with connectivity, and Verizon is known to be the best in the field," Hackel said.

Closely Guarded Secret

Apple, which didn't comment on the MacRumors report, has kept details about its prototype phones a closely guarded secret. In July, a 25-year-old worker at Foxconn, the Chinese iPhone manufacturer, reportedly committed suicide after a model in his care disappeared.

A further iPhone buzz was created by two recent Apple job listings seeking a software engineer specializing in advanced map applications.

Wired.com reported last month that Apple has purchased the online mapping company Placebase, a clear sign that the new phones will feature an enhanced map application, and fueling speculation that the new phones will no longer depend on services from Google, which is rumored to be developing its own smartphone.

Apple also added Placebase founder Jared Waldman to its team.

In related news, Apple sold an estimated 60,000 iPhone 3Gs on the first day of its launch in South Korea on Monday. Sales were much poorer for the product in China, where only 5,000 units were initially sold last month.

In the United States, refurbished 3G iPhones were a Black Friday hit, with AT&T selling 16GB units for $49.99 and higher-priced units on sale throughout the holiday season. AT&T said the phones were returned during the 30-day trial period and updated with new software.

Source: App Developer R...