Apple Inc. Chief Executive Officer Steve Jobs introduced the company's latest upgrade to its popular iPhone. The latest model will feature a global-positioning system and the ability to sync with Microsoft Exchange. It will also allow users to browse the Web faster. The new phone, which won't be available until July 11, will start at $199, making it cheaper than its predecessors.

Jobs also announced the creation of a new service called MobileMe that enables customers to sync content on their computers, iPhones, and iPod touch devices.

The iPhone's popularity has prompted rival phone makers to develop their own touch-screen phones. Here are a few that were recently introduced to the market.