Bell wears two cameras around his neck all his waking hours. One of them he calls a SenseCam. It takes a digital photograph every 20 seconds or so -- all day, every day, year after year. Soon you'll be able to buy a SenseCam of your own. (I'll tell you where - follow the link.)
This automated capturing of your life's events is called Lifelogging. It will take many forms, but I predict it will become a major trend -- like Facebook. What do you think?