Unlike some of the other names lauded at the time, Julie made a lot of money from her venture.

What began as a simple event, organised from the front room of her rented London flat, made the front page of the Wall Street Journal in 1999 when she launched it as a business in 17 European cities.

She later expanded it to more than 100 cities worldwide, and when she sold it two years ago for £32million she was a 25% shareholder.

For someone whose career is about encouraging venture capitalists to take risks with start-ups, it's a surprise to learn she was extremely cautious about how to invest her windfall.

"I banked a lot of it and kept it there," she says, "and I only invested a small part of it in my new company, Ariadne Capital. What I did invest was mostly spread across a range of private companies I have an interest in, and I only put a small part on the stock market and that's very diversified."

The Wall Street Journal named her as one of the top 30 most powerful women in Europe but she's almost too busy to spend money on herself. All the more reason she's particularly keen on one of her portfolio companies - TenUK and its website tenuk.com. It's a business that offers organisational services (like a personal concierge) to busy executives.

"They have a team of people who can manage tasks you don't have time to do and access a database of trusted suppliers to do it - it's just what I need," she says. "They can plan a party for you, buy some wedding presents, get your dry cleaning done, buy a car .. the list is endless. Plus they've built up relationships with suppliers so you can just tap into their tried-and-tested information." She was raised in Northern California and locates the origins of her work ethic in the example of her parents. Her father is the doctor who brought the practice of lung pulmonary medicine to California and he built the largest medical group in North America at the time. Her mother was equally industrious starting as a teacher and switching to a lawyer in later life. "Most people I have worked with find it difficult to keep up with my clock speed," she laughs. "I just have a lot of energy and passion for the things that I want to change in the world. And I track people who've been successful who have an abundance mentality, rather than one of scarcity."

She began by working as a marketing consultant in both France and America with companies such as Hewlett Packard, 3Com and Motorola. When she sensed opportunity in Europe she decided, at the age of 30, to study for an MBA at INSEAD in France, after which she joined a company called New Media Investors and met her First Tuesday co-founders.

"The only money that ever went into First Tuesday was my $80,000 and the other founders were absolutely thrilled that it was mine going in and not theirs. We split the stock equally four ways and nobody got diluted - it was just my bank balance that kept on getting lower and lower.

"But it's never been about the money. It's about creating a more level playing field so that smart people win. When I was in my mid-20's someone once said to me: 'Julie, don't ever do anything in your life because of money. Do it because it's where your heart is, do it because it's what you believe in.'"

She still lives in the same rented flat in which she started First Tuesday and won't buy a house because she's worried about being gazumped (and the corresponding waste of precious time). But don't mistake her failure to spend on herself for being frugal.

"I think you can be both frugal and also generous," she says. "I'm generous towards other people - quite a few people who've worked with me in the past have come to work for me at Ariadne. I think they feel I invest generously in them, but I'm very frugal with expenses and we run a really low cost, lean and mean operation."

Worst buy: A Peugeot 205 she used in France. "The French do many things wonderfully but I'm not a big fan of their cars."

Prefers to pay: By cash. This stems from her time as a student when she learned not to do much on credit.

Clothes: "I spend more on dry cleaning than on clothes. My wardrobe dates from five years ago."

Tip: She was a waitress in her college days, so tips at least 20%.

Greatest extravagance: "If I feel I need to be somewhere or be with someone, I will get on an airplane the same day. Some people think that's extravagant because you should plan your trips."

Collects: Entrepreneurs. "People I think have done something interesting."