Mr Culshaw is the principal architect of Wanaka company Pocketweb's award-winning Nokia cellphone application, Pocket Life, which allows cellphone users to share their present location and other places they really like with friends and family, via GPS and mapping services.
It works on the internet, too.
This month, Pocket Life was announced runner-up in the Forum Nokia Developer Community's 2009 Calling All Innovators contest, which attracted 1700 submissions from 85 countries.
The winner was Ground Guidance by a company called Primordial, which Mr Culshaw said was a terrain-based tracking system based on a United States military patent.
The runner-up prize package included about $20,000, which Pocketweb, a start-up company, will find very handy.
Mr Culshaw, a 40-something, married father of two, does not always embrace the technology.
He has days where he would happily hurl his cellphone into Lake Wanaka because he finds it so annoying.
He obtained a computer science degree from Cambridge University, in the United Kingdom, and then vowed never to touch another computer again.
A year in the British police force changed his mind and he ended up back in the information technology industry, working variously in Sydney, Auckland, and back in the UK.
So how did a small Wanaka company rise to the top of an international competition?Most importantly, Wanaka had the scenery and lifestyle.
Visitors from England and Germany fell in love with the town, immigrated, and started families.
Mr Culshaw, originally from Preston, Lancashire, England, met Michael Heinzel, of Germany, while they were picking up their children from Wanaka Primary School one day.
Mr Culshaw got talking to Mr Heinzel, and as their friendship developed, Mr Heinzel introduced his Sydney-based contacts, Dr Alexander Koeppen and Hanno Blankenstein.
Later, Terry Warwar, an Australian who now lives in Queenstown, joined the team.
"I was working in the travel industry, building travel systems... We slowly ended up as partners. That was about two or three years ago now," Mr Culshaw said.
The international recognition will be valuable as the company continues to grow.
But Mr Culshaw says neither work nor the social networking technology he designs will take over his life.
He is in Wanaka to live a healthy life and is not on the same level as the younger generations, who seem reluctant to be parted from their cellphones even in the shower.
He acknowledges the intrusive, "Big Brother" aspect to Pocket Life and other applications in development.
The worldwide technology emphasis on developing tracking devices and software potentially allows people to be in constant contact and have markers on other people's locations at all times.
But with Pocket Life, people can just turn their phone off.
And they can control what they want to share, Mr Culshaw says.
"For my age group, we are what I call the 'email age group'. Sometimes, we feel uncomfortable giving out emails because we get hammered [with junk]. But with the under-25s, it is all about social networking and Facebook, sharing photos...
"It is the next step because these people are willing. If people are prepared to share stuff and get back something for it... I have got to be open-minded about it because you can see these things happening. But older generations are generally more uncomfortable with it," Mr Culshaw said.
Pocket Life can be used to record and send the location of the user's favourite mountain-bike tracks, cafes, art galleries and suchlike.
It can also have early warning applications for things such as bushfires or hailstorms.
Or it could be used by multisport race support crews who need to keep track of their athletes.
It is best used in urban settings or where there is cellphone range.
"I wouldn't rely on it while out bushwalking. It is not a beacon," Mr Culshaw said.
For the environmentally conscious, however, Pocket Life can be used to record transport routes, work out carbon emissions and then choose the best route to reduce the user's carbon footprint.
Mr Culshaw also says Pocket Life might come in handy for concerned parents who want to keep track of teenagers. But at $800, it is expensive.
