These are the top information technology officers at some of America's largest Fortune 100 companies, the people charged with flying at 50,000 feet to spot important trends and oversee massive operations throughout countries around the world. Whether gamblers or penny-pinchers, collectively they must justify spending tens of billions of dollars on purchases that rarely show immediate returns on investment.

As a testament to their importance, today's chief technology and information officers have risen from relative obscurity to the highest ranks of such multinationals as Citigroup, General Motors and Procter & Gamble. Their role has expanded in the public sector as well, taking a higher profile in the federal government--especially since the exposure of technological vulnerabilities on Sept. 11.

Once overlooked or underestimated, these technology officers often wield influence second only to the chief executives of their companies. Even after the digital economy's precipitous drop, information technology remains a driving force in global corporate growth.

If the industry is going to stage a rebound, it will be Fortune 100 technologists like the men and women interviewed by CNET News.com in this special 10-day series who decide the timing and extent of any reversal of fortune.