The big box retailer Best Buy is set to become the first retailer outside of Apple and AT&T to sell the iPhone 3G in the United States on September 7. The company sports nearly 1,000 stores throughout the country that will dramatically increase the number locations potential iPhone buyers can purchase the combination iPod and smartphone.

Currently, Apple has 189 stores in the U.S. selling the iPhone 3G, and AT&T has about 2,000.

Best Buy completed a major revamp of 970 stores to include Best Buy Mobile, the company’s store-in-a-store for cell phone buyers, on August 6 ahead of its iPhone 3G roll out. The company has also prepared its employees to sell and support iPhone, according to president and COO Brian J. Dunn.

"Our Best Buy Mobile employees have the training and expertise to deliver the best experience possible for our customers -- from the initial purchase through the life of their iPhones," he said.

Along with selling the iPhone 3G, Best Buy will be equipped to handle the activation process, too. Apple and AT&T already require activation at the time of purchase -- a requirement for the lower price compared to the original iPhone -- and Bust Buy will be able to follow suit.

Like Apple and AT&T, Best Buy will sell the 8GB model for US$199, and the 16GB models for $299.

The added visibility that comes with placing the iPhone 3G in Best Buy locations could be good for Apple not only because more potential buyers will be exposed to the handheld, but also because Best Buy already sells the iMac and Apple’s laptops. Customers that are interested in the iPhone 3G but wouldn’t go into an Apple Store can still be exposed to the Mac, which is something that can’t happen in an AT&T store.