I'm always interested in the software people use to help their creativity, so I thought I should write up one of my favorites that gets very little attention. It's Keynote by Tranglos software and it's an open-source Windows-based tabbed notebook. Check out some screenshots here. Keynote sits in my system tray and I can hit CTRL-SHIFT-F12 at any time to call it up and start writing. Escape sends it back to the tray. Inside of Keynote, my first tab is a Notepad that I use for writing anything or saving temporary scraps of information. Then I have other tabs such as a "music" tab where I can enter potential song titles or ideas. It's a tree view so all I have to do when I have an idea is hit CTRL-SHIFT-F12, select the music tab, hit enter to create a new tree node, type my idea + enter and I'm done. I can also enter data in that node as well, such as lyrics or chords or whatever I'd like.
I've tried a lot of these programs and even though there have ben no updates to Keynote since late 2003, I haven't found anything that's as fast, feature-rich and simple to use. I'd recommend to anyone looking to capture their ideas or is just an information packrat.