The tiny clip-on Memoto camera takes two photos a minute. The Memoto app displays the GPSd photos on a timeline, so you can go back and see where you were at any point in the past.
The camera has no buttons. (That's right, no buttons.) As long as you wear the camera, it is constantly taking pictures. It takes two geotagged photos a minute with recorded orientation so that the app can show them upright no matter how you are wearing the camera. And it’s weather protected, so you don’t have to worry about it in inclement weather.
The camera and the app work together to give you pictures of every single moment of your life, complete with information on when you took it and where you were. This means that you can revisit any moment of your past.
I think it should have a pulse sensor on it so that when your heart rate increases, it starts shooting video.