AIR FRANCE Flight 3666, Seat 33C, 35,000ft above Nova Scotia

Eleven people got me on this flight: one amateur and ten professionals helped me limp to Heathrow Airport and up into the sky. Five of them, namely the taxi driver and airline employees, are directly paid to be friendly; five are paid to be stern. One, though I whisper this as he's in the seat next to me, is possibly my closest friend.

My bags are packed for a research project: I have a magnetic and a digital dictaphone; empty notebooks I've rendered less intimidating by wrapping them in duct tape; the best of Martha Gellhorn (to be given to a friend - more on Gellhorn later) and initials written on my hand that stand for nothing other than Studs Terkel, first and only name on my travelling book list.

I am travelling to America to interview friends, probably friends of friends and hopefully friends of friends of friends and what I am researching is simply them: one by one I'm going to ask them why, how and when they are friends of their friends and also ask them what they think friendship means, now and in America.

I'm interested in the economics of things that look like friendship and might or might not be, and in the mechanics, digital, vegetable and animal, with which Americans make and stay friends.

Economics: when the taxi driver told us his daughter works in the Empire State building he gave us something for free, something such as the security screener took from me when, as an exasperated father to petulant child, he barked 'You just can't leave that tray where it is! You just can't!'

Mechanics: read this blog and send me an email. I'll reply to it, I'll advertise your blog or your website here and if, as I hope, you know of someone who might like to be interviewed for this book, I will visit them and deliver to them something by hand. I'm going to be travelling from one coast to another, on the great highways of the twentieth century, and at the same time along what promise to be the great highways of the twenty-first: the social networks of the Internet that have at once collided the American coasts and made every corner of the States part of the heartland.

In more precise terms - and if these entries reek too strongly of Hemingway, I hope it is merely in avoiding the abstract when the precise will do - this means I will be knocking on doors, usually announced but always unsure of what the welcome will be. I will be handing over parcels and asking, in return, questions that I myself would struggle to answer (my sleeping schoolfriend kicks out as I write). The project relies on the openness and hospitality of strangers, and it's my faith in American warmth and enthusiasm that makes me worry less about the chances of success. All I have to offer is my own enthusiasm and a present or a message from a loved one.

In two hours the project begins: two weeks in and around New York, two weeks back in the UK to

1. deliver items by hand picked up in the USA
2. learn to drive
3. shake off the aftereffects of a broken leg

then back to the USA to continue the travels for as long as the networks of friends or the US Government allow. This first post has focussed on me, more than I would like, but I hope now just to pull aside the curtain and introduce the players themselves: the interesting people I'm lucky enough to know already and those I'm looking forward to meeting. This is a travel blog and a mass biography, the story from one particular viewpoint of America in 2009.