The iPhone's design is simple, sleek and to the point. It's a candy bar and not a clamshell style smartphone, however. And if the popularity of cell phones like the RAZR's proved in recent years, sometimes people require their ultra-modern mobile handset to be flip phone. Hence, Apple's most-recent iPhone-related filing - called "Dual Sided Trackpad" - with the U.S. Patent office.

Apple's new patent application clearly shows Apple is, at least intellectually, playing with the iPhone's form factor to, no doubt, look into ways to broaden the appeal of the already popular smartphone. Of course, Apple being Apple, the application doesn't describe your average flip-style phone. It goes a lot further.

The iPhone pictured in the filing's diagrams sports a shape and size much closer in style and maybe even size to Apple's latest iPod nano models than today's iPhone. Unlike the current iPhone, it is divided into two part parts, though.

The touch sensor and display have been split up. So the screen is on the top panel and touchpad on the bottom panel of the clamshell.

What's most interesting about this design is that the touchpad is transparent and is sensitive on both sides of the panel. This is called dual-sided capacitance touch technology by Apple. And it opens up a whole slew of possible input combinations, not available in today’s iPhone.

The Photoshop renderings below, put together by Unwired View, offers an excellent view of what Apple is describing in the patent application and what’s possible should it be put into place in a real device.

Looks like Apple's got something in store for those who want an iPhone but will only consider using a flip phone and nothing else. We’ll keep you posted.