MediaWiki

MediaWiki is a very useful thing to install on one's laptop for personal note-taking purposes. Doesn't take too much to set it up, and once it's up and running it requires little further maintenance. Your own personal wikipedia for all your note-taking needs. Very useful for cross-linking and organizing countless notes from paper notebooks and disorganized text files, which I am now in the process of doing.

It's also got me using it to finally create a decent .plan file for myself, rather than the one I've been keeping spread out across a handful of livejournal posts.