What it means: At the supermarket checkout in front of you, there's a nerdy chap with some strange contraption affixed to the side of his head. It's a camera, automatically snapping photographs at regular intervals – by the end of the day, he'll have thousands of digital snapshots, capturing his entire day's activities in megapixel detail, and adding to the already-vast archive of his life. You have just met a lifelogger, a person who records every boring aspect of their daily life for posterity: eating breakfast, travelling on the bus, going to the bathroom, and most likely seeing their therapist about their obsessive behaviour.

Where it comes from:The makers of Big Brother realised people would gladly sit for hours and watch other people do very little, but lifelogging began as far back as the 1980s, when Ontario super-geek Steve Mann first strapped a computer/camera contraption to his head and started gathering continuous data. Soon, his Wearable Wireless Webcam was transmitting his life 24/7 for a community of lifeloggers. Now, everyone's getting in on the act, putting their lives online for people with lots (and lots) of spare time.

How to say it:"Pete got bored with lifelogging, so he strapped the camera to his dog – it's the biggest thing on the web!"