Mobile phones have shaped global communications. But who shapes mobiles? BBC News speaks to Jan Chipchase, principal researcher at Nokia Design.
Jan Chipchase's most recent report was called Where's The Phone?
Jan Chipchase tours the world looking at how people use mobile phones in their everyday lives and, more broadly, how people live.
"This is my office, my workspace," he says, pointing to a map of the world.
In the last 12 months he has visited 15 countries, carrying out eight full-scale research projects.
Mr Chipchase's focus is on the uses to which people put their phones; where they keep them, how they answer them, and a million other details about our relationships with these devices that have helped shape our world
On the street, in homes, in the office, in pockets, handbags, at the marketplace, and in the community - Mr Chipchase tries to put mobile phone use into the context of the culture and landscape he is in.
His research has included looking at home battery charging services in rural Uganda, street charging in Kampala, how illiterate people use a mobile and more recently where we keep our phones.
From city bankers to shantytown dwellers, and from hip teens to octogenarian SMS fiends, no use of a phone is too trivial; no detail of a person's life too insignificant.
"I specialise in human behavioural research. It often starts with a very simple question like 'what do people carry?'.
"This is interesting to Nokia because we want to put things in people's pockets - something of value.
"If you can understand one element of that value then you can understand people's motivation."
Mr Chipchase takes a team - designers, psychologists - into different countries around the world, to look at people's lives in different contexts.
"I want to understand what people do and why, and pretty much in every context. We want to know the secret stuff as well."
But why would Nokia pay someone like Mr Chipchase to travel the world and to have all of those experiences? Where is the value in that?
"We do this research work to inform and inspire the design stage. To bring designers into the field so they know whom they are designing for.
"Often designers are designing phones for markets they have little experience of - so we want to bring the world to them and them to the world."
Mr Chipchase works three to 15 years ahead of the market. His team carries out research using a method called convergent validity - it is not quantative scientific work but qualitative.
"We deal with informed opinion. If we do our jobs exceptionally well, then it is very informed opinion."
So where is mobile phone design heading? Will they get ever smaller, perhaps becoming part of our clothes rather than as a single unit?
Mr Chipchase says the important consideration is how people behave, not what the latest technology can do.
"It's about what to design and when to design, because human behaviour changes very slowly; technology changes very quickly.
"If I can understand why, for example, a lady in north east China carries her phone on her left wrist, then we can understand others' motivations."
He adds: "It's also about what not to do with design. We have lots of assumptions about the world around us - Nokia is no different.
In Asian countries phone straps have become very popular
"If we want to remain relevant in all these markets we need to know how our assumptions differ from other people's."
To date, Mr Chipchase has had two patents granted based on his work, and a further 25 are currently being considered.
By 2009 more than four billion people in the world - out of a population of 6.3 billion - are expected to have a mobile phone connection in their lives.
"The challenge for a company like Nokia is to sell products to all these markets - all of which have different needs.
"We want to meet the needs people have, rather than just putting technology out into the market place."
Mr Chipchase and his team employ a number of techniques - from shadowing people's lives, talking to as many local people as possible and documenting their lives in different contexts.
"I spend a lot of my time looking into people's bags and handbags - with their permission, of course.
"There's a whole load of stuff in life that is worth documenting. You see it every day but don't even notice."
He adds: "We spend as much time as possible being in the places that people do what they do. The mobile phone is used from when you get up in the morning and is often the last thing you interact with at night."
He has studied the mobile use of low-income manual workers in China, and spoken to blind people who are experts in using a phone and not having to rely on a screen.
"If we were to try and design a user interface for someone who is not looking at the screen, someone walking along and wanting to get a phone number, then a blind person is the ideal person to speak with."
Typically, Mr Chipchase is to be found discovering people and cities on a bicycle or on the back of a motorbike.
"I buy a lot of bicycles. I have huge time pressures when in these places and I want to engage with the local population as much as possible.
"I find buying a bicycle is a great way to stay in touch with people. We give the bicycles away at end of the study."
The hardest part of his job is not the jetlag, dealing with bureaucracy or coping with different languages, explains Mr Chipcase.
"The question is how can we do our job as a large corporation and show people we interact with sufficient respect."