Facebook Leads Nonfriend Field As We Rank Tech's Testiest Titans

Ali vs. Frazier. Yankees vs. Red Sox. Bird vs. Magic. Sports are full of great rivalries. So is the fast-paced, ultracompetitive tech industry. Some rivalries get nasty, with executives bad-mouthing opponents, running attack ads and filing lawsuits. Some rivalries cool over time, while others go on for years -- depending on circumstances. Wireless carrier T-Mobile USA had been running ads mocking AT&T's (T) service. But when AT&T announced its