An iPhone model that doesn't officially exist began appearing recently in one developer's application analytics, possibly indicating that Apple is field testing the next version of its combination iPod and smartphone. Apparently Pandav's iBart application has been showing usage from an iPhone model identifying itself as iPhone3,1, which is a higher number than any of the current shipping models, according to Mac Rumors.

iPhone2,1 identifies the current iPhone 3GS and began appearing in developer's logs several months ahead of its release, too. The iPhone3,1 identifier first appeared in the iPhone's firmware back in August, leading to speculation that it would be used with the fourth generation model.

Apple isn't saying what it plans to pack into the next generation iPhone, but that hasn't stopped the rumor mill from speculating that it will include a multi-core processor and compatibility with Verizon's cell service. Assuming Apple sticks with its established pattern, the next iPhone model should roll out sometime in July or August 2010.