One of the greatest advancements seen with iOS4 is the multitasking capability. You can now switch between apps quickly and return to the previous state of each app without hassle. Apple is not using conventional multitasking method – known for draining battery life and damaging overall performance – and instead introduced their own brand of “multitasking”. When you switch to other apps, the one you previously use is actually paused and sent to the phone’s internal memory. This results effective yet efficient multitasking capability as seen on the iPhone 4.

Another interesting feature you will also see is simple personalization features. You can now change the home screen’s wallpaper and add different personalization to the handset. Apps will also organized in folders for easier access in general. You will find the new iPhone 4 superbly convenient to use.

Last but not least, you will also find a new feature introduced on the iPhone 4 and iOS4 in particular: FaceTime. FaceTime is a new video call app designed for iPhone users. The platform is also available to other companies who want to create FaceTime compatible apps, and it is only expected that further developments are just around the corner.

The new built-in camera is now capable of capturing crystal clear images without hassle. This is possible because Apple enhanced the imaging sensor used on iPhone 4 all the way to 5-megapixel. Not only that, iPhone 4 is also equipped with built-in LED flash to make shooting under difficult lighting condition even easier. To top it off, iPhone 4 is capable of recording HD video; we are not talking about barely-there HD video recording at all, and you will notice that right away once you see video footages recorded using iPhone 4.

Multimedia playback features are also among the major features available on iPhone 4. You can play high definition videos – including the HD video footages you recorded using iPhone 4’s camera – without hassle. Couple the superb HD video playback capability with iPhone 4’s new Retina display, and you have unrivaled portable media player with you at all times.

Of course, you can still play tunes and audio files without hassle on the new iPhone 4. Simply keep the media player running while you use other apps to enjoy music no matter what you do. No performance decrease at all even when you are multitasking with heavy apps that require a lot of resources.

IPhone 4 is one capable device nonetheless. Priced at merely $199 for the 16GB version and $299 for the 32GB version (US price, with AT&T service plan), this is the kind of mobile phone you will pick right away. Avid Apple fans were lining up in front of stores even weeks before the iPhone 4 was officially for sale. With new Retina display, superbly elegant industrial design, and tons of additional features – including the new iOS4 – iPhone 4 is worth every penny.

When compared with iPhone 3GS, iPhone 4 is way ahead. But that doesn’t necessarily mean you should upgrade to iPhone 4 right away. There are several things you might want to consider before you make the decision. If you got your iPhone 3GS just recently, you may want to wait for further iPhone 4 releases before you upgrade. Those with limited budget can also restrain from upgrading to iPhone 4 and simply resolve to installing iOS4 on your iPhone 3GS. If you have older version of iPhone in hand, upgrading to iPhone 4 is the best way to go indeed.

If you compare the iPhone 4’s new Retina display with the one used by iPhone 3GS, you will quickly see just how improved it is for sure. When compared briefly, the two screens show huge difference; iPhone 4’s screen is a lot brighter and present better viewing experiences altogether. We even took our time and compare the iPhone 4’s display with displays of other mobile phones, and it is safe to say that the Retina display used in iPhone 4 is in fact the best there is today.

The size of the screen is exactly the same compared to iPhone 3GS – iPhone 4’s screen is also 3.5” – but the display is now capable of displaying 960 x 640 pixel resolution. Not only that, the overall pixel density is increased all the way to 326ppi. Let’s not forget that the new Retina display also offers 800:1 contrast ratio, so you don’t have to worry about not being able to use your iPhone 4 conveniently even under heavy sunlight. This is one remarkable improvement that will make iPhone 4 even further ahead.

The main improvement seen in iPhone 4 would have to be the newly introduced A4 processor used exclusively on iPhone 4 and iPad (at least for the time being). Instead of using the old Samsung ARM processor, Apple decided to go with the new and improved A4 processor. This processor is the core of iPhone 4’s snappy performance and responsive operations.

Couple the A4 processor with upsized 512MB RAM, and you have one snappy mobile phone capable of completing multiple tasks with ease. You can expect unrivaled performance from the new iPhone 4 nonetheless; the combination of these two main ingredients are simply perfect, proving Apple’s hard work throughout the iPhone 4 development stages.

You can choose between 16GB and 32GB of internal storage depending on your needs and budget. Offering larger internal storage such as 64GB or even 128GB will surely make the iPhone 4 looks even more appealing, but Apple is clearly trying to reach wider market segment and to keep their prices low.

A well-placed 802.11n Wi-Fi radio as well as a quad-band HSUPA chip and Bluetooth v2.1 enhances the iPhone 4’s connectivity options, although using the new Bluetooth v3.0 module could’ve make this phone perfect.

It is safe to say that the iPhone 4’s exterior design is more than just stunning. The phone feels like high-end mobile phones – for example Vertu – in hand and it is certainly more than just stylish. The iPhone 4 also makes older generations of iPhone seems old and bulky, even though it is only slightly thinner when compared to the iPhone 3GS.

Two pieces of reinforced glass is used on the back and front faces. The front part also functions as medium for the new – and also improved – capacitive touchscreen developed exclusively for the iPhone 4. The back plate is mainly for aesthetics, but it surely makes the phone looks elegant in every way. In between the two layers is a metal strip forming the sandwich, functioning as the handset’s main skeleton as well as antenna for enhanced network reception.

The simplicity of iPhone 4’s exterior design reminds me of classic brands such as Leica. Being simple and functional is exactly what iPhone 4 is trying to do, and the device exceeds available mobile phones by quite far indeed.