If you’re an iPhone developer with access to a paid developer account with Apple, you can upgrade your iPhone to the latest beta 4 release from Apple’s official developer site.

This latest beta release seems to have got the long overdue feature, that is Internet Tethering. This feature was actually introduced in iPhone OS 3 last year but was never served by AT&T to their customers. According to experts, it’s because AT&T’s network is not capable of handling huge data traffic. Recently, AT&T announced that they’ve updated their network to reach out to many users. And so, the iPhone OS 4 beta 4 release has a sign of it.

Now, iPhone OS 4 Beta 4 allows users to setup a new tethering account either by calling or visiting their site. This clearly shows that, AT&T has taken an action to serve their customers.

As this is just a beta release, the look and feel of the new tethering set up wizard might vary with final release.

iPhone OS 4 Beta 3 seems to be quite more stable than that of Beta 2 of iPhone OS 4. It has brought some great tweaks which all the iPhone developers were looking forward to.

The most important feature which was lacking during the previous beta release of iPhone OS 4 was to quit more than one running App at a time. In order to quit the App we need to tap and hold the running App in App switcher, apps wiggle and has red minus symbol to quit the app. Until now, the app which you were tapping and holding to quit, only that app was showing red minus symbol. In this release, that has been resolved and now whatever app you press and hold to wiggle, all has red minus symbol to quit the app in App Switcher.

Now, the most important feature which every iPhone user were waiting for, since the release of 1st generation iPhone in 2007 – the ability to lock the screen orientation. When the iPhone was first unveiled in 2007, the accelerometer was very unique feature of it. Turn to landscape for landscape orientation and back to portrait for portrait orientation of screen; in Safari, Photos, etc. It was the beginning of iPhone. Now, it has completely changed the way you do your day-to-day work. People were finding problem with it. We can’t read New York Times easily when we are in our bed, it change its orientation too frequent. Now, in Beta 3 release of iPhone OS 4, lock orientation has been added which I believe is the major tweak that iPhone developers would love. Earlier iPhone application developers had to add their own screen lock orientation feature in their App.

There is one more feature spotted. The iPod controls widget in App Switcher. When we double tap the Home Screen key the App Switcher shows up. Now, if we just slide to extreme left we will find the iPod controls & a screen orientation lock key.

Overall, this Beta release of iPhone OS 4 is more stable than any other previous Beta releases of iPhone OS 4. We’re still fetching some more update info on it. If you’ve spotted some more updates on this just fill us up through the comment form.