Apple (NSDQ: AAPL) has invested in Imagination, a small chip designer, which plans to to power the graphics in future iPhones and iPod Touches, CNet reports. The British company announced today that Apple has acquired a 3.6 percent stake for 3.2 million pounds, or about $5 million. Imagination does design chips for a number of applications, but its focus is on a powerful one made for mobile phones.