Bump into an old friend, get chatting but have to rush off. Facebook me, they say. Wait, you say, I’ll take a photo of you with my smart phone and then click the ‘Find’ button on this new Facefind app I just downloaded. Facefind would use facial recognition software to match the photo you just took to photos on Facebook and suggest the person as a friend. You can then click the ‘Ask to be friends’ button.