11. Apple and Google

Frenemies since: 2006, when Google CEO Eric Schmidt joined Apple’s board of directors.

Acts of friendship: Schmidt’s continued presence on the Apple board; the existence of Google Maps and Gmail on the iPhone; Google’s status as default search engine in Safari; the fact that Macs are so popular at the Googleplex that conference room tables are equipped with MagSafe power adapters for MacBook-using meeting attendees.

Acts of enmity: The moment that Google announced its Android open-source mobile OS, it became Apple’s principal rival as a developer of next-generation operating systems for phones. And both companies make browsers for Windows, although Safari and Chrome ultimately compete more with Internet Explorer than each other.

Current state of the frenemyship: Actually, the two companies still seem to still along just fine for the most part, although Steve Jobs did earnestly tell the New York Times that he thinks Android “hurts [Google] more than it helps them.” And wondering how long Eric Schmidt’s role at Apple can (or should) last has become a popular parlor game.

(Photo of Steve Jobs and Eric Schmidt by AP)