TiddlyWiki
TiddlyWiki is "a reusable non-linear personal web notebook" written in HTML, CSS and JavaScript to run on any modern browser without needing any ServerSide logic. Mokurai has it running on an XO, and would be happy to give a demonstration to any interested group. It can be installed on a computer directly, or kept on a USB key so that you have it with you no matter what computer you are working on. The TiddlyWiki site offers a multitude of tiddlers--TiddlyWiki plugins--including calendar, address book, and many more.
I was lucky enough to be able to test-drive a TiddlyWiki based application - http://reiber.org/PaulsConsultantsNotebook.html - on Edward Cherlin's unit. It appears to work pretty well! I haven't tried all of the various functions by any means (there are probably a thousand plus potential QA tests in there) but what we did run, ran great!
-- PaulReiber
