A guide to creating a baby journal with TiddlyWiki.

http://a-penguin-in-redmond.blogspot.co.uk/2014/02/creating-baby-journal-with-tiddlywiki-5.html

Keeping a journal about your baby is fun. It allows you to keep track of those events in your baby's life and development that are most important to you, and to tell them in your own words. [...]

There are plenty of online services that can help to keep such a diary, but you need to have an internet connection to access them, and you have to trust them to keep your data safe.