Happy Colors
I use text files to organize myself. The main file is a to-do list which keeps track of the important stuff for the next few days; there are several project-specific files where I keep information about projects that I work on, etc. Plain text files (especially viewed in a good editor) are an amazingly powerful tool.
My editor of choice is TextMate - it's a sort of mac-specific emacs or vi, only friendlier, prettier and easier to learn. It's very extensible - not programatically, like emacs, but you can still do a lot of useful stuff. Have a look at the website if you're curious.
Over weeks and months of using text files as an organizer, I've developed some syntax elements - mostly borrowed from other languages - that I use. Wouldn't it be nice if TextMate would at least pretty-color my files, the way it colors source code of Python or C? Sure it would. So I started to create my own language template, and my text files are coming to life. I want to teach it to understand my indentation, and to do some auto-complete.
My text-based organizer is becoming a happier, more welcoming place, which must be a good thing. :)