Cool, I actually used TiddlyWiki before I found org-mode
Plus, I use it for more than just organizing information. Like writing reports and authoring HTML and PDF content with embedded R code for example, which obviously is not the point of TW.
Org-mode is essentially to organizers as Emacs is to text editors, i.e., slowly becoming a platform of its own.
Two org-mode posts at the exact same minute
All this and it's Free Software, too. The mailing list and community is one of the most responsive out there. I've heard many people say that learning emacs is worth it just for org-mode alone.
Check out http://orgmode.org/worg/org-tutorials/index.php for more use cases and tutorials/talks. Incredible piece of software, cannot recommend it enough.
Emacs org-mode (http://orgmode.org). Your life in plain text. Nothing else compares.
You sound like you'd benefit highly from Emacs org-mode (http://orgmode.org), which functions not only as a day planner and TODO manager, but a plain text authoring system. You can export to many targets, including both LaTeX and HTML. If you haven't seen it yet, definitely check it out, the community is great and the project is growing daily. The latest big inclusion is the ability to embed executable source code for literate programming.
UHF reference! Totally forgot about this awesome movie until now.
Adding features does not necessarily increase functionality -- it just makes the manuals thicker.