What do you guys use to write a personal journal, notes, and reference information that you want to group and search through later?

I'm not one of those crazy people who likes to share their journal with the world. Some things I like to keep to myself. It's quite nice to have a reference.

Preferences for cross-platform stuff (windows, mac, linux)

Some Background

For Windows, there's a program called Yeah Write, which really changed my expectations about how easy it should be to start writing something. You don't open or close files -- just click an empty slot and start writing, or click a filled slot to work on another file. And you can organize things into categories by creating tabs.

Now that I carry a Macbook, I've just been using TextEdit. I like it because I can't lose my work when my computer crashes: it auto-saves everything and restores it when I launch TextEdit again. But I make a mess, leave thirty open files, and save everything to one directory with no tags for easy grouping. Saving files and selecting the directory they should be in is too clunky to do in the middle of a meeting. And organizing files into folders in the Finder is a pain, since there's no tree view like on Windows. Sure, I'm lazy, but I miss Yeah Write. I'm not going to get a windows laptop just to use it though. Since the laptop I take my notes on is a mac, I'm gonna be biased toward mac solutions.