[_phred]

There's nothing like good old plain text. :)

Nowadays I'm downright spoiled and use org-mode[1] to keep my systems journals. Org files are plain text as well, and org-mode takes care of setting up the tree by date. I can also add a journal entry from anywhere in Emacs with just a couple keystrokes, which makes it incredibly low-friction to use.

Like I said, the most important thing is to TAKE NOTES. Even pen and paper. It's one of Limoncelli's big points in Time Management for System Administrators.

Tooling doesn't really matter, the important part is being able to remember what the heck I did and when I did it. Invaluable for troubleshooting.

[1]: http://orgmode.org