Apple used its Worldwide Developers Conference (WWDC) to unveil the iPhone 3G S, that features improved performance, longer battery life and an autofocus camera and video recording.

The iPhone 3G S offers speeds up to twice as fast as the iPhone 3G, according to Apple. This is real speed that can be realized in launching applications and rendering Web pages. The new iPhone also takes advantage of the OpenGL ES 2.0 standard for 3D graphics, allowing games to render better than ever, the company said.

One of the really cool features of the iPhone is the autofocus camera. During the demonstration at the keynote, Apple showed how the camera could focus on different items by simply tapping on them.

For instance, if you are taking a picture of a flower with a house in the background, you can focus on the house by tapping on it. The house then becomes the focal point of the photo and the camera focuses on that.

The new iPhone also comes with one of the most requested features from users: Video recording. When you enter the camera interface with the new iPhone, there is a slider that will change your camera from still mode to video mode.

A voice control feature in the iPhone 3G S gives you hands free operation of popular iPhone and iPod functions. Perhaps the funniest parts of voice control is the ability to create a genius playlist on the fly by saying “play more songs like this.”

The new iPhone also includes built-in Nike + iPod support, a digital compass and of course, the over 100 new features that will comes as part of iPhone OS 3.0.

One of the highlights of the keynote was the demo of a new feature called Find My iPhone. This is a new feature for MobileMe users that will allow you to find your phone and see its location on a map. You can send the phone an audio alert, even if the phone is in silent mode, allowing you to locate it.

If you discover the iPhone is lost and you can’t recover it, you can send a remote wipe command to completely wipe the phone of all its contents.

iPhone 3G S will be available in the US on June 19 and will cost $199 for the 16GB model and $299 for the new 32GB model.