Fresh from telling his mum about the wonders of Pompeii, Green raves about the ease of communicating in Europe.
"I remember being at a hostel in Wanaka and it cost about $10 for 24 hours of wifi. Here you just rock up, some of them don't even have passwords, you just sign in and you're away. So we can spend our downtime updating our family and friends, posting photos and we can stay in contact so easily. It's really good."
It seems like the perfect way to travel - always connected, updating your loved ones about your trip in real time and keeping in touch with all the news and personal relationships back home.
But according to Massey University social anthropologist Chris Howard, there's a potential dark side to our constant online presence, which could be undermining the whole idea of travel as the ultimate getaway from our daily routine.
Howard spent more than three months in the Himalayas doing his PhD research, not on the local people but on Western travellers in India and Tibet. His thesis started with the idea of travel as modern-day pilgrimage but increasingly he realised that 21st century travellers have changed - arguably for the worse - from the old days of sending a letter or postcard home every few weeks or even checking their emails in an internet cafe every few days.
"I noticed a kind of habit," says the 32-year-old Californian.
"They would feel they would have to spend an hour or two each day keeping up with all the things going on. It really blurred for me the lines between work and leisure... the idea of getting away from it all. These days what interested me was that 'it all' comes with you, because it's so accessible."
Feeling like a spy, Howard observed travellers in cafes and other wifi hotspots, scanning Facebook, wearing giant headphones as they called home on Skype, sending and receiving emails and doing mundane chores like online banking that people used to ignore when they left home on an extended holiday. Some were working as they travelled. One student was "living pretty well" as she used her Australian scholarship to complete her thesis online.
The flipside, says Howard, was the loss of downtime and the opportunity to make friends with other travellers in the traditional way. Everyone in was in their own personal bubble, more connected to their friends and family back home than their fellow travellers in the Kathmandu hostel common room. During the day many took constant photos or videos, which they would post that night - or straight away if they were competitive - and receive online comments in return, which affected their perception of their trip.
He calls it a constant feedback loop, which overtakes the experience of seeing a local village or enjoying a mountain hike in the first place.
"What's ironic is that they would seem to be documenting their experience for the purpose of creating a memory of it... but you wonder about the actual quality of the experience. What kind of memory is it apart from; 'I was there, I was walking around taking photos and posting them'?"
People's behaviour only changed when the wifi disappeared, says Howard. He remembers time slowing down in the remote, disconnected village of Yuksom in northeast India. Travellers at the local Yak cafe sat at the big round tables and talked to each other.
"It felt like what travelling used to be like before this information bomb."
In an Auckland backpackers hostel in downtown Fort St, half a dozen travellers sit in the common room, each focused on their personal devices. Singaporean university students Mohammed Jahafar, 24, and Celestine Kok, 22, who arrived in New Zealand only a few hours ago, are planning their two-month trip around the North Island, which so far includes a visit to Lake Taupo and - for Kok, at least - going skydiving.
The couple, who have travelled overseas before, both spend about two hours a day keeping in touch with close friends back home and sharing their experiences on Whatsapp and Facebook. Like many travellers, they also use the technology to plan ahead, having online conversations about where to go with other travellers on backpacker websites.
Both have smartphones and Jahafar also carries a laptop, as they are thinking about a working holiday. Jahafar thinks backpackers still talk to each other but agrees with Howard that feeling the need to go online can diminish the value of travel.
"We feel that we're obligated to share this experience, which is supposed to be intimate and personal for us, with everybody else. And ultimately we fail to realise that these things don't actually translate over the media because... when other people see the pictures or the videos, they don't feel as much."
He does take pictures and post them at the end of the day but tries to keep the number down.
"It's our experience, we are here, we should be in that moment."
Howard sees the preoccupation with being connected as a creeping threat to the Kiwi ideal of the Overseas Experience or OE, which has become a rite of passage for generations. One of the key ideas behind the OE, he says, is that you leave the structure of your normal life behind, which allows you to try new experiences and bond with people who would normally be outside your social circle. In his thesis, which is sprinkled with personal travel anecdotes, he gives some bizarre examples from his trip, including
• An impromptu stay with a Malaysian family in Kuala Lumpur followed by a rush to hospital after their 16-year-old son caught his hand in the blender.
• Missing his next flight that evening and coming down with food poisoning which left him sick for the whole trip.
• Getting locked in a pitch-black hotel shower during a power cut in Kathmandu.
Clearly stepping outside your comfort zone doesn't always go well, says Howard, but it does transform you as a person, however slightly. Being online stops this break occurring.
"Home accompanies you into these other places and keeps on following you and reminding you that you haven't actually left. The getting away from it all becomes problematic.
"Most people I met in the Himalayas wanted to have an adventure... If you're just going round and getting online and seeing what Auckland is up to, you're still on your social network and it's business as usual. So what happens to the adventure?"
Jude Wilson agrees. The experienced traveller and author of Flying Kiwis: A History of the OE says she was amazed how often recent OE Kiwis in London kept in touch with home, frequently texting every day and emailing or Skyping every second day.
"I saw it as being a real shame in that they didn't get that real separation from home that I always thought the OE was about.
"Getting out there and making it on your own is not quite the same if you're asking mum and dad what to do and keeping them in the loop. It's not necessarily misbehaving and not telling people, but just having your own experience that you don't necessarily have to share."
Wilson spent most of the 1980s and 1990s away from New Zealand, travelling about half the time. Now aged 57 and a tourism researcher at Lincoln University, she still travels regularly with her netbook and likes checking out her accommodation in advance on Google Maps but confesses to being a reluctant online sharer.
"You get sucked in to feeling obligated to keep people up to date and part of me resents the fact that the world is forcing me to do that. It's hard to resist and I long for the days when I went travelling. It was three months straight and nobody knew where I was."
Wilson doesn't want to romanticise the old days.
She says the nature of overseas travel is always changing - we no longer go to England by ship or follow the 1960s hippie trail overland through Asia - and part of the reason she hardly ever rang home was that it cost so much and the connection was so bad.
Howard is also careful to say that his unease about online travelling is just a personal opinion. He understands that just as roads and electricity have ended the traveller's dream of a Shangri-La-style lost paradise but generally improved the lives of local people, it would be unrealistic to expect Western travellers to give up their instant digital connections with home.
He can even see the irony of his own online dependence while travelling - originally he planned to use only a notebook but his journalist brother told him not to be so stupid, so he took an iPhone.
It made his job much easier and saved his sanity on some horrendously long and bumpy bus journeys when being in the moment was an unattractive option.
But he thinks there is a wider issue about our constant connectedness. Some of his students have up to four devices in front of them in class but struggle to concentrate on a lecture for more than a few minutes.
"Our bodies are becoming synced in to the technology.
"We touch these screens and we put our presence in there and that goes out to the world and feeds back into ourselves - so these technologies become an extension of our bodies."
It sounds like science fiction, he says, but humans have been moving away from nature and towards technology for thousands of years.
The worrying part is that as a new generation of toddlers use iPads before they can walk, we still have no idea about the long term effect on human behaviour.
Wilson believes many young travellers do wrestle with their online dependency.
"Quite a lot of them ... still found it hard to step away from it. It's making a conscious effort - kind of like going off the grid."
Back in Naples, Jake says over Viber that he's been checking times online for the boat to Capri. He doesn't mind keeping in touch with his parents while he's away - "I think my mum especially just wanted to know that I was okay," - but he has been thinking about about how much he uses his phone.
"I think I've put about five photos on Facebook. I want to focus on what we're doing.
"Also I don't want to seem like I'm bragging about being overseas. People say they want to know but you don't want to be too in their face about it."
Opting out of the instagram race
Derek Cheng's reaction to seeing the Sahara Desert two weeks ago was to stop and admire its incredible beauty.
"I just wanted to walk through the dunes and feel the sand between my toes. That's the way I wanted to experience it - other people were taking panoramic photos and saying; "Yeah, that's my next Facebook cover shot".
Cheng, a 35-year-old former Herald journalist who now works for the APNZ news agency, is a seasoned traveller who has spent about four of the past six years on the road, including a year in Asia. He took a course in vipassana meditation in Nepal, which involved living for 10 days in total silence like a Buddhist monk, and loves to disappear into the mountains for up to a week at a time. Not suprisingly he didn't take a smartphone travelling with him.
His father bought him an iPhone before his last trip, as his parents worried about him mountain climbing alone, but he doesn't like using it.
"Personally I don't think you need them... You know, not having that itch in your pocket where you're thinking; 'I wonder if someone's emailed me?' It makes you more present, I think."
He feels the demands of social media have taken over in other areas too, like live music - "everyone is recording videos instead of watching the concert".
Cheng concedes travelling with a smartphone can be useful. He remembers a friend using an instant Mandarin translation app to ask a flabbergasted old man in Taiwan for directions to the nearest guesthouse. But Cheng still feels uncomfortable about the socially competitive aspect of posting the best, fastest photos online to rack up Facebook likes or gain Instagram followers.
Cheng recalls heading up Kala Patthar, a popular trekkers' spot with a stunning view of Mt Everest. His group got there early before sunrise and poured cups of tea from a large thermos for other travellers as reached the top.
"We just sat up there for four hours, just watching and being there. It's just so beautiful. Most people just get to the top, take their photo and go back down."
