Yesterday, in a blog posting we reported that Apple Computer shares rose after investors speculated on whether the company was working on an iPhone, which would meld together an iPod and a cellphone.

Many of the details were unknown, but today, another Wall Street analyst said that Apple Computer is poised to launch its own wireless service that piggybacks on the Cingular Wireless network. The model, called mobile virtual network operator, enables Apple to sell the service directly to the customer by acquiring wholesale capacity from Cingular Wireless.

The note was written by UBS AG telecom analyst Benjamin Reitzes, who speculates the company would then sell its much-rumored iPhone music player/networked handset across its 174 retail outlets.

In a story on Barron's Online, it looks at the challenges facing Apple should it end up doing this.