Adam,
I've been thinking the same for a while.
I need a more detailed record of my life.
And it's not because I'm forgetful but because it's the little details of our lives that elude us, and because it's amazing how we think we remember much more clearly than we actually do.
As for my specifications:
I also wanted it to be online, but it has to be secure.
For me a wiki doesn't cut it, because I need dates -time- to be the core of the archiving system. The rest will be indexed with tags.
I was leaning towards a private and local install of wordpress.
Doesn't it allow to keep a blog private?
You could even have it online.
Plus everything is stored as a mySQL DB.
So in a nutshell it would be like an innerBlog (inBlog??)
Does anyone have any experience with this setup?