Windows: If you're a fan of hierarchical notes and you want a lightweight and portable way to take them, Noteliner is a simple and free outliner application.
Noteliner was born when Sam Hawksworth wanted a simple and lightweight way to take outline-style notes. It's tiny — a mere 416k! — stand-alone, and extremely easy to use. You can run it the moment you finish downloading it, no installing or unpacking necessary, and from the first line of notes you being taking it automatically starts the outline structure for you — no fiddling with settings or even hitting the TAB key necessary.
On top of a solid outlining system Noteliner sports some additional features like the ability to collapse notes, break up your notes into separate pages to create a more notebook-like feel, and interactive bullet points. Any bullet point on the outline can be clicked on to change it from whatever bullet point shape it currently is — square, circle, etc — to a bright blue star for highlighting and a dimmed checkmark to indicate something has been accomplished and checked off.
You can read more about Noteliner at the author's site below or, if his site is straining a little under the influx of traffic, you can download Noteliner from the via link at Freeware Home. Noteliner is freeware, Windows only. Have a favourite lightweight note taking and/or outlining application? Let's hear about it in the comments.