Voice recorder
A voice recorder is a very useful device. It helps save transitory impressions – you no longer need to scribble them down in a notebook. I recommend recording the summary of each day. It can later be used for writing an article or simply for reminiscing. Naturally, if you have a camera, you no longer need a voice recorder.

Instead of a voice recorder, you can also use a camcoder or a digital still camera capable of capturing voice notes or movies, or a mobile phone.