The mac users among my readership might want to check out VoodooPad. Not hugely revolutionary in that it basically does what a wiki would do, but the automagic insertion of links if you type a word which exists elsewhere is quite shiny. Remains to be seen whether I can be arsed to get out my laptop every time I want to reorganise my life, though. :-)

For Windows users, WikidPad looks to be quite similar. Seems like it might be compilable for other OSes, too.