Apple plans to introduce a new version of the iPhone in July that comes equipped with support for faster 3G networking. And the new version of the popular smartphone will be available for a dramatically lower price.

The 3G iPhone, unveiled by Apple CEO Steve Jobs at the end of his Worldwide Developers Conference keynote Monday, will sell for US$199 for the 8GB model and $299 for the 16GB model. That's a $200 discount from the previous $399 and $499 prices for the 8GB and 16GB iPhones, respectively.

Shipping July 11 in 22 countries, the 3G iPhone will enable faster data downloads over AT&T's 3G network. The handset will also include built-in GPS.

Physical changes to the new iPhone include a curvier design, full plastic back, solid metal buttons, and a flush headphone jack.

In addition to the new features, iPhone 3G offers an improved battery life of 300 hours of standby time. Users will also be able to switch between 3G and 2G in case they wish to save battery life. On the new iPhone, 2G talk time has improved to 10 hours (from 8 hours); for 3G talk time, the phone will have a battery life of 5 hours.

The 8GB model is available in black; the 16GB iPhone now comes as a white phone.

We'll have more details on 3G iPhone later Monday.