Dec 10, 2008
TiddlyWiki - http://www.tiddlywiki.com/
TiddlyWiki Markup - http://tiddlywiki.org/wiki/TiddlyWiki_Markup
TiddlyWiki (wikipedia) - http://en.wikipedia.org/wiki/TiddlyWiki
You may also be interested in Wiki on a Stick - http://stickwiki.sourceforge.net/
By the way, TiddlyWiki almost works on my Nokia n800. I may read and edit files properly through the built-in Opera browser, but I cannot save them. There is an Opera work-around, TiddlySaver, but it relies on a .jar file and the n800 has no Java support. Pity!
UPDATE: The http://www.checkettsweb.com/tw/gtd_tiddlywiki.htm + n800 temptation made me fiddle a bit more, and saving now works! (after confirming the unsafe operation 4 times :-) All it takes is commenting out or deleting line 549 of the gtd_tiddlywiki.htm file -- the one with saveTest() -- before your first use. And if you have basic Unix command line skills, here is a quick and dirty script for launching your little agenda from the command line, showing the day's entries (if you copy-paste you shall see the entire lines):
sed -i '/<div tiddler\="DefaultTiddlers"/s/\[\[.*\]\]/\[\['$(date +%d\\\/%m\\\/%Y)'\]\]/' \
dbus-send --session --print-reply /com/nokia/osso_browser \
--dest=com.nokia.osso_browser com.nokia.osso_browser.open_new_window \
... assuming the file resides in /media/mmc1/gtd. Backups will be placed in /media/mmc1/gtd/twBackups.