The Associated Press___ Silicon Valley isn't sharing Facebook's misery MENLO PARK, Calif. (AP) â¿¿ Silicon Valley, it turns out, doesn't revolve around the stock prices of Facebook and its playful sidekick, Zynga. By most indications, tech companies in this hub of innovation are humming along, even as two of its rising stars endure steep declines in their stock prices that have wiped out more than $60 billion in wealth in the past six months. Companies catering to mobile devices, business software and data management products are thriving, while longtime Silicon Valley stalwarts such as Apple Inc. and Google Inc. remain among the most revered brands in the world. ___ T-Mobile launches campaign to lure iPhone users NEW YORK (AP) â¿¿ T-Mobile USA, the only "Big 4" phone company that doesn't sell the iPhone, now wants to snag used ones from AT&T. Starting Wednesday, when Apple is expected to reveal a new iPhone model, T-Mobile will start advertising that AT&T iPhone owners who are out of contract can switch to T-Mobile. Apple Inc. hasn't said anything about a new iPhone, but it is expected to announce the iPhone 5 at an event it has scheduled in San Francisco on Wednesday. Sales would likely start later this month. ___ China's imports shrink in sign downturn worsening BEIJING (AP) â¿¿ China's imports shrank unexpectedly in August in a sign its economic slump is worsening, bad news for exporters elsewhere that count on the appetite of the world's second-largest economy for natural resources and industrial components to offset anemic Western markets. The Chinese president warned growth could slow further, prompting expectations of possible new stimulus spending. Imports declined 2.6 percent from a year earlier, below analysts' expectations of growth in low single digits, data showed Monday. That came on top of August's decline in factory output to a three-year low and other signs growth is still decelerating despite repeated stimulus efforts.