In the early hours of Monday morning, British explorer Daniel Hughes made the first ever video call from the summit of Everest - 29,029 feet above sea level at temperatures of -35°C.
The expedition was sponsored by, among others, HTC - and Hughes used the company's HTC One handset to make the world's highest video call back home - chatting live to the BBC.
Hughes climbed with mobile satellite technology provided by Immarsat which allowed him to share updates on the climb and post to social networks like Facebook and Twitter. He also courted the internet meme machine by filming the world's highest Harlem Shake video.
“This project has been two and a half years in the making and it’s hard to put into words how amazing and surreal it is to be speaking to London from the highest point in the world," Hughes said.
"The support for the expedition has been phenomenal and thanks to the interactive nature of the climb, I really felt like I had everyone behind me."
Along with some fantastic PR for HTC, the expedition aims to raise £1 million for Comic Relief. Hughes got involved with the charity after a 2010 trip to Bolivia and placed a red nose at the summit of Everest to show his support.
Of course, if you're planning to take a wander up Everest yourself then there are worse phones you could take along than the HTC One. The new device has been getting positive reviews from critics and the sheer demand is forcing the Taiwanese company to step up it's production cycle.
"We pride ourselves on being at the forefront of design and innovation and the HTC One was put to the ultimate test in extreme conditions, where it was able to help Daniel connect to everyone back home – even from the top of the world,” said Suzi Watson, a spokesperson for HTC UK.
“We’re truly proud to have been part of Daniel’s amazing journey," she added.
Check out the video below to see Daniel's live call from the top of the tallest mountain in the world.