The U.S. Patent the US Patent & Trademark Office (USPTO) recently published a patent application, filed on the part of Apple last summer, to bring native instant messaging to the iPhone. A feature common to nearly all high-end feature phones and smartphones that's been lacking in the iPhone from the beginning. Whether it is a patentable feature is open to question.

Be that a sit may, the filing - entitled Portable Electronic Device for Instant Messaging, describes a system similar to the iPhone's SMS bubble-chat interface with dedicated text field for entering new messages, as Apple Insider points out, but with some important differences (see picture).

As you can see, the application makes no mention of SMS in the drawings; although it does so in the text of the filing. Rather, IM is written in the images instead. The system described in the patent application may be able to be used for sending and receiving MMS (Multimedia Message Service) messages, which are those that feature pictures or video. That's another feature, like IM, lacking in today's iPhone.

                                     Current SMS app setup on left, Possible future IM app setup on right

Here's the patent filing's abstract:

A portable electronic device for instant messaging is disclosed. One aspect of the invention involves a graphical user interface (GUI) on a portable electronic device with a touch screen display. The GUI has a set of messages exchanged between a user of the device and another person. The set of messages are displayed in a chronological order. In response to detecting a scrolling gesture comprising a substantially vertical movement of a user contact with the touch screen display, the display of messages are scrolled in accordance with a direction of the scrolling gesture. The detecting of the scrolling gesture is substantially independent of a horizontal position of the user contact with the touch screen display.

Since Apple's iPhone SDK for developing third-party software doesn't allow for developers to create applications that run in the background, which is essential for a native Instant Messaging program to do its job, it is important that Apple bring this service to the iPhone itself. If this just posted patent application is accurate, then that may be exactly what Apple has planned.