Now, he's produced a remarkable series of cellphones engraved with Vietnam-style war slogans.
They feature peace symbols and inscriptions like, 'May God have mercy on my enemies, because I won't', 'Hearts and Minds', 'I'm sure to go to heaven because I've spent my time in hell', and 'Iraq 2003 - 2009 - No better option?'.
During the Vietnam War 1955 - 1975 nearly all US soldier carried a Zippo lighter.
"As the soldiers were initially forbidden from modifying the exterior of their uniform they would use engrave their lighters to express their feelings and sentiments," said the New York-based photographer.
"Looking at the original lighters it seemed nothing had really changed from what I was hearing was the current feelings of soldiers fighting in the modern day wars."
So he decided to recreate the Vietnam Zippos with the same sayings, but replacing Vietnam with Iraq and Afghanistan, and updating the cigarette lighters to cellphones, which he imagined would now be the soldiers' closest personal possession.
"Moral wise nothing has changed and again history repeats itself not learning any lessons for its past," said Hargreaves, 34.
He cited the example of a friend, 'Connor', who served in the Laghman Province in Afghanistan.
Connor said the soldiers serving there "had accepted their fate as being damned to an eternity in hell like it was a joke".
"When things are so bad the final defence you had was your sense of humour," says Hargreaves.
"He requested I do one final phone with what had become the new slogan of the army 'Hearts and minds,' but the reality couldn't be further from this he told me."
Hargreaves, who went to school at Christ's College in Christchurch, has completed an exhibition of to-go coffee cups from cafes around the world.
His recent work can be found at henryhargreaves.com.
