Having a great time working with Workflowy.com, and thought I'd show you what I'm talking about. Here's a little sample of my current Workflowy:
All you have to do to make this work is type a quick entry, then hit return. You're taken to the next line If you press TAB, then you move over one "level" and the next thing you type will be beneath the header your typed before.
Once you have an outline, you can collapse different parts of it, or you can click a header and see only a given section of the outline on a single page in your browser. You can share those different parts of your Workflowy with other folks, mark items complete, even hashtag items and then search on the hashtag.
It's really intense given how basic it is, and I'm still having fun with it. I don't do everything on my list, of course, but it's nice to try and keep up with everything.