Esther Dyson has been a leading technology visionary for decades. In fact, she was working with the internet years before you even knew it existed.

The daughter of a physicist and a mathematician, Dyson spent her early working life as a journalist (she was as a fact-checker and reporter at Forbes) and then spent time in the late '70s as an investment analyst with a firm that managed investments for the Rothschild family. Following a stint at Oppenheimer, she joined Ben Rosen's Rosen Research. Dyson eventually purchased the company from her boss and she renamed the company EDventure Holdings. One of the earliest tech speakers and commentators on the web, Dyson produced a popular tech-industry newsletter (Release 1.0) and organized regular conferences and events for the industry. She quickly became one of the best connected players in Silicon Valley (despite the fact she lives in New York) and both an in-demand speaker and board member.

In 2004, Dyson sold EDVenture to CNET for an undisclosed amount, but she stayed on until 2007, when left to advise several start-ups close to her heart, including several in the commercial space travel sector. She's also quietly invested in a handful of Web 2.0 companies, like Technorati, Flickr.com, and Eventful.com and has since shifted her focus on preemptive healthcare technologies. [Image via Getty]