Apple is negotiating with Microsoft to replace the default search engine in the iPhone OS, two anonymous sources say. Discussions have been in progress for weeks, according to claims, and would potentially see Google swapped in favor of Bing. The positioning is an important one, as most mobile advertising is now viewed on iPhones and iPods, and people are more likely to use the default search option. To use Bing on Apple handhelds at the moment, people must either load the Bing app or visit bing.com.