Perhaps the most tantalising lost camera story in the world is the one that came out of Britain's 1924 expedition to climb Mount Everest. This was one of the earliest attempts to reach Everest's summit, but ended in tragedy when the two leading mountaineers, George Mallory and Andrew Irvine, disappeared and were later found dead near the mountain's peak. Although not present on his recovered body, Mallory had been carrying an early Kodak camera with him which he would have used to document a successful ascent. Nobody knows whether he and Irvine actually made it to the top and were killed on the way down rather than during the upward climb, but if Mallory's camera were ever discovered the mystery could possibly be solved one way or another by developing the film secreted inside it.

Finding a lost camera somewhere near the top of Everest, in amongst all those towering ice shafts and jaw-like crevasses sounds a bit like finding a needle in an angry haystack. This is (almost) the exact analogy used by a Facebook user who found a lost camera on holiday in Greece and wanted to use the powers of the world wide interweb to somehow get in touch with the original owner and return it. The user, Danny Cameron, uploaded a handful of photographs developed from film found inside the camera to a dedicated Facebook group ('Needle in a haystack') and asked the network's community if anyone recognised the people depicted in the pictures. The images aren't historically significant or artfully-shot, but interest in the group spread like wild-fire, and over 200,000 users signed up in fascination with the project over a matter of weeks. On November 3rd the group reported that the camera's owner had, at last, been found.

Cameron posted the following message of thanks and celebration: "It was a massive mobilization of virtuous people. I was amazed and in awe of them all. I couldn't have done it without 235,000 other people though, and a grand and unintended outcome of it all - I believe - is that I have given people encouragement that honesty still exists in the world, and so hopefully I have inspired the people on the group to be more considerate in their daily lives, because being kind is a great human trait and there are one thousand people doing one thousand nicer things than just returning a camera."

In response to the news a member of the group wrote, "This group gave me so much hope, and I'm glad the camera owner has been found. I'm going to stay in the group just to remind myself that life's possibilities are endless."

But the greater human good doesn't always triumph in these things. Another story of a lost camera is a rather more sorry tale of thievery and dishonesty. Despite examples like this, the 'needle in a haystack' project certainly captured people's imaginations and conversations began to spring up on the group's discussion board about what sort of people the unidentified holiday-makers in the photographs were. Where did they come from? How long ago had the camera been lost? What would their reaction be should they get it back? There was even an excited report about the whole thing on the Sky News website which was posted the day before the search came to an end.

This is far from the first time that the internet has been commandeered to try and find the owner of a forgotten camera. This group achieved success after a much smaller number of Facebook users joined, and a completely different website, The Found Cameras and Orphan Pictures blog, is surely the true home of photography-themed lost-and-found on the web.

The blog is becoming a well-recognised starting point for kind travellers who've come across cameras dropped in bits of unsuspecting undergrowth or left behind in bus and train stations all over the world; or indeed for those who've lost their treasured DSLR or compact and are actively trying to get it back. For more gratifying tales of humanity's good deeds, you might want to head straight to their list of success stories. A recent 'orphan picture' uploaded to the site is this one of a mother and her new-born baby (see below right), which is as emotive a lost photograph as you could get. The quality of the snap suggests it might have been taken some time ago. Looking at it you end up wondering whether the hours-old child in the image is now an adult whose proud young mother has grown into an older woman.

Maybe that's why so many people are ready to express a desire to return images like these to their originators. Photographs, however casually they might have been taken, or later misplaced, are intensely personal objects and their real meaning is defined by some familial knowledge of who is depicted and what that moment in time signifies. Without that knowledge there is a nagging sense of detachment and disruption, which is probably why the term 'orphan pictures' seems so appropriate - and also why our imaginations tend to run wild when we see strangers smiling at us. The photographs are, after all, emblems of the people they represent. They are so much the physical and emotional property of another person that it seems only natural that they would be missed, and that we would want to give them back.