A while back I was listening to a show on journal keeping. Some of the guests were concerned that people who keep an electronic journal might lose those precious memories fairly easily. While I agree that it is much easier to lose things on the computer it is also easy to lose a paper journal in a fire, flood, etc. Losing a hard drive is just much more likely than a natural disaster.

They also had an interesting point about email which are the new letters. Email, like snail mail of old, is a very good source of what happened in your life. I have 5 binders full of emails from just 95-98 when I was not as heavily into email as I am now.

Of course, people who became famous (and died) have had their journals, letters, and other personal writings published in books. It is better first source history.