Rumors are fling around that suggest Apple is building a search engine.
Currently Apple is using Google as default search engine on Safari browser and the iPhone. Google of course pays a bundle to Apple for this arrangement.
To run a search engine is not core to Apple though. Microsoft has one that nobody uses, Apple would have the same issue. Apple could buy Yahoo though. It gotten really cheap now after this back and forth with Microsoft and Apple has a huge pile of cash lying around.
TechCrunch has looked into the Apple Search Engine Rumor more closely and checked to see if Apple is hiring Search engineers, which it has not so far.
TechCrunch rather guesses that Apple is building a new interface for search for the iPhone that is more attractive, but would use still Google results.
More details on TechCrunch.