iPhone challenge for Apple inc

With more than 128 million iPhones sold since 2007, the device''s ubiquity has created a marketing and design challenge for Apple Inc.: how to dazzle consumers in a maturing smartphone market where many alternatives now look and feel like Apple''s gadget. That''s a challenge Apple will have to address Tuesday, when the company is widely expected to unveil a fifth-generation iPhone, said the Wall Street Jounal Monday. Apple has been working on an iPhone that is thinner and lighter with an improved eight-megapixel camera but details otherwise are unclear. Now the question is, what features will be sufficient to impress consumers. For years, Apple has won converts in part because of the freshness of the iPhone''s design and software capabilities that didn''t exist elsewhere. The company now faces tougher competition from smartphones using Google Inc.''s Android software, which also feature full-screen touch displays and access to thousands of apps. Some phones even out-flank the current iPhone: Motorola Mobility Holdings Inc.''s Droid Bionic has an eight-megapixel camera and access to high-speed, fourth-generation wireless networks. Android accounts for 43% of the U.S. market for smartphone operating systems, while Apple has 28%, according to Nielsen Co. Apple still is the biggest producer of smartphone handsets. Some surveys have suggested that consumer demand remains strong for the iPhone, which was last refreshed in June 2010. A survey by ChangeWave Research in July found that 46% of consumers planning to buy smartphones in the next 90 days would choose an iPhone. Demand could be bolstered in the U.S. by the expected agreement by Sprint Nextel Corp., the country''s third-largest mobile carrier by subscribers, to sell the handset  +