The issue of third party applications for the iPhone is an important one. While Apple and its partners such as Google will be making all sorts of programs for the gadget, they simply cannot cover everything. Furthermore, the iPhone will be running a version of OS X, which means that it will have the potential to run just about any kind of application. However, there is a delicate balance to be struck here and Apple is taking no chances.

During the open Q&A portion of Walt Mossberg's interview with Steve Jobs at the D: All Things Digital, the Apple CEO touched on the subject. When asked by an audience member about writing applications for the iPhone, Jobs said that Apple ultimately wants both the iPhone to be secure and open without compromising either attribute. The last thing Apple wants, he suggested, is an iPhone that can be easily hacked or that crashes as a result of installing third party software.

"I think sometime later this year we will find a way to let third parties write apps and still preserve security. But until we can find that way, we can't compromise the security of the phone. Nobody's perfect, but we sure don't want our phone to crash. We would like to solve this problem, if you could be just a little more patient with us, I think everyone can get what they want," he said.

Whatever solution Apple finally settles on, developers will have their work cut out for them if they want to port their programs to the iPhone, especially the designers. Despite the device having OS X and being theoretically able to run any application, programs will require a new interface. With no mouse or keyboard in the classical sense, not to mention menus or such interface elements, even the simplest of programs will need some rethinking in order to work well on the iPhone.