Carly Fiorina's fall was every bit as dramatic as her rise. When she was named CEO of Hewlett Packard in 1999, the high-tech industry in Silicon Valley was completely dominated by men. Yet she was feted and celebrated for much of her time at HP. Fortune put her at the top of its Most Powerful Women list for six years straight (1998-2003); but her push to merge with the computer company Compaq was a controversial move that put her on shaky ground. Despite doubling the company's revenues, in 2005 she was fired-- a move she claims was politically motivated. Fiorina has since entered the political fray, stumping for John McCain and putting a female-friendly face on his campaign. She ran for the Senate seat in California, challenging incumbent Barbara Boxer, despite a recent battle with cancer.

