It all began in 2007 when Apple introduced the original iPhone and the large and capacitive touch screen display started to charm the consumers.

The Cupertino tech giant followed up with subsequent releases of iPhone 3G and 3GS, holding on the basic form factor of the original model. However, the new models did feature a new black plastic surrounding and casing.

Apple finally offered a completely redesigned iPhone with the release of iPhone 4 in June 2010, featuring hardened glass on the front and rear coupled with an oleophobic coating to stamp out the smudges.

As in the case of the iPhone 3G and 3GS, Apple stuck with the same physical design of iPhone 4 when it launched the current model of the device, iPhone 4S, in October last year. The stunning glass enclosure of both the models is surrounded by a stainless steel band, which also serves as an antenna for Wi-Fi and cellular network data.

Yes, it has been just three months since we started experiencing iPhone 4S, yet speculations about the possible design, aesthetics and specifications of the next-generation iPhone have already started playing with consumers' imagination.

Nobody can guess what the new model of the popular smartphone will look like until Apple itself makes any revelation. However, that doesn't stop various designers and enthusiasts to release their own exclusive concepts of what they think would make a viable iPhone 5.

Here are two mock up concepts of the next generation iPhone. While one is betting on an A6 dual core processor and a 10-megapixel, the other one replaces the Home button with two separate Home buttons on each side of the handset. Let's have a detailed look.

Concept 1: Meet 'iPhone SJ'

Earlier this month, Antonio De Rosa, founder of ADR Studios, came up with a fine concept of the future smartphone from the Apple camp. Dubbed the iPhone SJ, the concept included a completely glass capacitive screen on a polycarbonate lightweight body.

Although De Rosa didn't dwell much into the technical aspects of the device, he did mention that his design was inspired by the to-be-expected A6 dual core processor, and an improved 10-megapixel camera, according to Redmond Pie.

People have reportedly gone wild over De Rosa's concept, which prompted him to post a few more images of what he thinks the next iPhone would look like.

[Photo credit: Antonio De Rosa, ADR Studios]

The concept of the iPhone SJ has been welcomed in an amazing and unexpected way by the Web. We want to celebrate all this by releasing more images and details of the concept together with a small video, De Rosa updated on the ADR Studios Web site. Check out the video below.

Concept 2: Designer Kris Groen Plays With the Home Button

Since 2007, the iPhone has received significant design overhauls, but one feature that has remained consistent is the Home button. Designer Kris Groen targeted that and has re-imagined the iPhone by completely removing the Home button from its original place.

He, instead, adds two separate Home buttons on either side of the iPhone bezel, positioned mid way up. According to Groen, squeezing both of the Home buttons together would take the user directly back to the Springboard. They will also allow faster app switching when pressed individually.

Groen has also increased the screen size to 4-inches diagonally with attractive Retina display.

I absolutely love what Kris did with the home button. This also seems to take from what Jan-Michael Cart envisioned for multitasking, but with added buttons that make it even better, said Jamie Young of AppAdvice. The ability to fully control the iPhone with only one hand is pretty spectacular.

Check out the video below.

Do these concepts have all what you like to see in the future iPhone? Will Sir Jonathan Ives and his team find something worth following in these concepts? Let us know your thoughts in comments.

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