A few short years ago, Apple sat on top of the smartphone world relatively unchallenged. As time has passed, other manufacturers have pumped money into their own development programs and closed the gap considerably between Apples flagship iPhone and their own handsets. In an attempt to stand head and shoulders above the competition once more, Apple has unleashed the iPhone 4.

The successor to the 3GS, the iPhone 4 has some improved innards that improve performance. Apples A4 chip powers the iPhone 4, which happens to be the same one found in the iPad. Though not quite as fast as the 1GHz claimed by the iPad, the iPhone 4s CPU still performs admirably. Graphics and navigation are rendered quickly and it would seem that anyone with serious speed complaints is merely nitpicking.

Viewing those graphics is accomplished on a 3.5 inch screen. Though not as large as screens found on some comparable models, the iPhone features what is known as the Retina Display. It boasts 960 x 640 pixel resolution and an incredible 326 ppi pixel density. So named because it reportedly displays images in more detail than even the human eye can distinguish, Retina more than makes up for any lack of screen size. Due to the incredible resolution, blurry and pixilated images are of no concern at all. Many testers of the iPhone 4 claim that they have never seen images so clear on any other handset.

The iPhone 4 also takes advantage of its Retina Display by improving on the meager 3 megapixel camera found on the 3GS. A new, 5 megapixel camera replaces the old and includes a backside-illuminated sensor more sensitive to light. The LED flash, like most flashes of its size, can over-illuminate the photographs, but the iPhone is adept at producing high-quality photos without flash and at low light.

Perhaps the biggest addition to the iPhone 4 is the ability to multitask. Some critics have voiced their displeasure that the handset doesnt offer true backgrounding (the iPhone lets a few APIs that approximate backgrounding to operate at a time), but it is close enough that most users wont have a problem at all. Apples claim was that they didnt apply multitasking to their smartphones due to battery drain. Now that this is not an issue, the iPhone 4 has been noted for its battery life, approaching nearly 40 hours of normal use in some tests.

With the iPhone 4, Apple has once again established itself as a leader in smartphone technology. With a Retina Display that none other can boast and improved performance, they have set the bar high. Not only has Apple won again, so have their customers.