TiddlyWiki

Simon (my new professorially endowed friend) put me onto this a while back. TiddlyWiki is a single html file which has all the characteristics of a wiki - including all of the content, the functionality (including editing, saving, tagging and searching) and the style sheet. Because it's a single file, it's very portable - you can email it, put it on a web server or share it via a USB stick.

Its cool and I have been using it for days. I have a GtD tool and personal research notebook up and running in an afternoon. I plan to play with this over the next few weeks and focus on using to actually manage my GtD workspace. I'll write up how that works soon.