Apple’s iPhone 3GS was available for half its current price at Wal-Mart Stores on Tuesday, signalling a potential clearing out of inventory before the company refreshes the product line later this summer, notes MarketWatch. Retail giant Wal-Mart  began selling the 16GB version of the iPhone 3GS for US$97 on Tuesday, according to the company’s website. The device still sells for US$199 via Apple’s own website.