Apple's comeback kid did it again -- but this time, the hurdle Steve Jobs overcame concerned health. At the end of June, Jobs, a pancreatic cancer survivor, returned to work after taking a leave of absence in January, citing health issues. It was later revealed that Jobs received a liver transplant. Investors questioned Apple's decision to hold back information on Jobs' condition, and the controversy hit at the heart of a nagging question: What would Apple be without its co-founder's business acumen and laserlike focus on design? After Apple ushered in the personal computer era with the Apple II and reinvented the PC with the Macintosh, the company's proprietary-systems strategy headed for a dead end and Jobs was ousted. Apple's fortunes languished. But after Jobs' return in 1997, Apple launched a succession of hit products including the iPod, the iPhone and a revived Mac using Intel chips. Apple is again a driving force in IT, but while Jobs' latest return has quieted the distress of Apple fans, issues about the company's dependence on him linger.

Microblogging and social networking have been the butt of cynical jokes as entertainers like Oprah Winfrey jump on the Twitter bandwagon to solidify their celebrity. But Twitter, it turns out, can be a vehicle for much-needed real-time information. The re-election of Iranian President Mahmoud Ahmadinejad over challenger Mir Hussein Moussavi caused chaos in Iran. With Western journalists booted out of the country, in June local Twitter users stepped in, sending out a stream of Twitter messages that helped the world follow events as protesters marched. The U.S. State Department even asked Twitter to postpone a planned service outage. Twitter has also been used to broadcast information by eyewitnesses at many other news events this year. But with the good comes the potentially bad: Twitter in Iran also was used in denial-of-service attacks against key government officials.