Esther Dyson is at the cutting edge, the queen of the Internet. Her ideas make things happen: Bill Clinton knows that, so does Bill Gates. See her CV and she sounds scary as hell. But Ann Treneman had her one- to-one and she was not afraid.

Esther Dyson is one of those women to whom very important people pay attention. People such as the Bills (Gates and Clinton). Her high- technology conference attracts everyone who is anyone in America and her opinion is enough to make or break any high-tech venture. I was not surprised to hear that after our interview she would be meeting Marjorie Scardino, head of Pearson. What would they talk about? "Oh Marjorie's got a little idea up her sleeve and so we'll talk about that. Last night at dinner we talked about Rupert. In my industry everyone talks about Bill. In yours, it's Rupert."

She smiles and the 46-year-old looks about 10 years younger. I'm not capable of smiling back, however, because I am terrified. This is because, on paper, Esther Dyson is terrifying. The New York Times has said she is the most powerful woman in the Net-erati. Vanity Fair ranks her as one of the 50 most influential people in the New Establishment. When powerful people want to know something about the future and the Internet, they know who to e-mail.

It takes a nervous minute or two to figure out that Esther Dyson is much nicer in person than on paper. True, her father is a brilliant physicist and she went to Harvard at age 16. True, she does run a company devoted to emerging technology and writes the industry's most influential newsletter. In addition she logs 250,000 air miles a year, speaks fluent Russian and received a $1 million advance for her new book. But she also has a handshake that is as light as a feather, a nice way about her and a wicked sense of humour. Her dress sense is supremely relaxed: for our meeting she is wearing jeans, pearl earrings and trainers. Actually she didn't wear the trainers for long. Within minutes she has taken them off. She did this in the hotel lobby yesterday and a porter asked her to put them back on.

She thinks this is funny. She laughs as she speaks, rather softly and slowly for a New Yorker. "Yes, I do like to see myself as approachable. Some people are just so scared of me that they don't notice that I am approachable." I pretend I do not know what she is talking about and ask her why they are so scared. "Oh you know, they have read all this stuff about how influential I am." She shrugs. "You know it's my job to be approachable. I represent the little guy. That is what I do. I shine the spotlight on little things whether it is a crackpot new idea or an obscure little country or a cute little company."

At the moment, though, it is her job to sell her book. Release 2.0 is a guidebook for the digital world for Everyman (and woman) and Esther is in London for two days to talk about it. Her schedule is jammed. When we met yesterday at 10am she had already been for a swim and answered some of the 67 e-mails she had received since the night before. She is a whirlwind. Last Thursday she had dinner with a friend in California and since then she's been to been to Seattle, New York, Zurich, Kiev and here. I say that she is a living e-mail. "I do travel a lot," she says with another laugh.

Swimming is the only constant in her life. Every day, no matter where she is, she ploughs a pool for an hour and she's got the chlorine hair to prove it. "I feel as if I'm getting unkinked somehow. I think about what I did yesterday - how I screwed up or what I did right - and I think of what I'm going to do next." Occasionally she brings pen and paper to poolside and jumps out to jot down a thought or two. "But I don't like to do that. I don't get mystical about it but it's the time for thinking about things overall, in context, rather than making lists."

So how does she actually describe herself? "Well I wrote the book, in part, to have a business card really. Now it could say Esther Dyson, author of Release 2.0. When I cross a border into a country, I have to say what I am. Sometimes I say financier, sometimes I put software writer, sometimes I write author and sometimes entrepreneur. I'm sort of like the Net, I'm decentralised."

Esther Dyson sees the Internet as something that is going to shape every aspect of our lives. "I'm not in love with my machines. I am in love with what they let me do. It's the capabilities that I like." She is an optimist: for her the Net can be used to better our lives, to enhance our relationships and to make the little guy more important. The balance of power will tip more towards the individual and Esther's message is that business, government, education and even parents should be ready for it. Her book is full of great, swooping ideas and little anecdotes that make you see that she really is talking about people, not computers. The reviews have not been ecstatic. "They don't really take on what I am saying. They say I'm being naive and optimistic but they do not even pay attention to ideas like decentralisation. Large corporations and governments are facing an erosion of their power and authority, not to one person or thing in particular but to everything else in general. Everything is much faster and more fluid."

Few people - and even fewer computer types - are able to talk like this and you can see why the Bills of this world seek her out. Perhaps, I say, she should see herself as a philosopher. She grimaces: "I try not to be too pompous. I see myself as a court jester. The important thing is to take other people seriously and not yourself."

Esther Dyson is a great fan of sig files on e-mails. These are automatic signature lines that say who you are, give a physical address and perhaps a motto or two. Her motto is "Always make new mistakes!" She likes people who are big enough to say they were wrong. She freely admits to making many mistakes: in investments, in interviews, in life. "I can be pretty rough on people in my office. You tend to do that to people who can't answer back and fortunately my business partner was able to say: `Esther, shut up and grow up. Just because you're unhappy don't inflict it on us.' "

All of this is most interesting because Esther Dyson is often portrayed as a lonely spinster oddball who spends her existence toiling away in a tremendously messy office in New York. She herself has said that she lives on the Net but clearly this is not true. She lives on a plane and spends her life meeting people, talking, networking. She is portrayed as an eccentric who doesn't have a home phone but I notice that she manages to use my mobile pretty adroitly when need be.

She not only speaks for the little guys, she sees the world as they do. When talking of a dinner she was invited to, she added: "They told me I was on table nine and I thought, `I hope I don't end up with a bunch of dogs'." I laughed and thought that it is doubtful that she ever would.

`Release 2.0: A Design for Living in the Digital Age' by Esther Dyson is published by Viking (pounds 15.99).