The problem with them for me is that they are on the web. If it's not a desktop app in which I store my data in files local on my machine, I'm not interested. I use OneNote today and am very happy with the note-taking aspect. It has no todo list or mind-mapping management so I have other apps for those.

If you prefer a desktop app for offline use (not just for privacy) then it can be done using something like Gears or Air. The app might save some or all notes locally and sync them when necessary. With a web app you can work from other computers/ platforms and mobile devices (android, iphone, netbooks). Don't you think that's important?

For quick notes I use a clean little OSX desktop app called Notational Velocity[1]. The only thing I would want in a dedicated note taker that it doesn't do is sync over the internet.

1- http://notational.net

I use Steven Frank's W2 wiki. It's a basic Wiki, supports Markdown, in PHP. Meant for the iPhone, but I use it on my Mac too.

Doesn't support mind maps, lists, etc of course.

http://code.google.com/p/w2wiki/

I just use OmniOutliner Pro.