Ready to get your Bing on, iPhone owners? That curious little Microsoft search engine you shrugged off just a few months ago could become a mainstay in your daily routine if BusinessWeek's sources are correct. According to a pair of persons familiar with the matter, Apple and Microsoft are discussing dropping Google as the default search engine on Apple's somewhat popular handset -- talks that have been underway for "weeks," apparently. BW paints the move as further evidence of an escalating rivalry between Apple and Google. In fact, one BW source claims that, "Microsoft is now a pawn in that battle." No doubt, the once cozy relationship has seemingly fractured with Google CEO Eric Schmidt vacating Apple's board and Apple recently snapping up Lala and Quattro Wireless -- acquisitions that some analysts see as defensive measures against a rapidlyencroaching Google. Isn't competition fun?