Gretchen at The Happiness Project has a nice little idea to keep a journal of one sentence entries. She allows some flexibility to include the occasional two or three sentence entry and skip a the odd day, but the system is there.
Why do this?
My hope is that, years from now, when I’m trying to remember what life was like at this point, I can look back at my one-sentence journal.
The effort involved with keeping a regular journal can be daunting for some people, such as Gretchen, when you really just want to capture what was going on in your life at that time.
Short and sweet and to the point, you are forced to only write the most important things and how you actually felt over the entire day.
There’s an obvious interest in this sort of journaling with popularity of Twitter and Jaiku. Maybe try updating these only once a day. Keeping a personal book does have more charm and, probably, longevity.