I've blogged before about using trac as a personal wiki, and that has been working very well for me.
But of course the day would was bound to come when using the text box in a web browser was just too painful. I want to use emacs to edit the text, and do so painlessly.
Of course, I should have realised before that someone else would have already done the hard work:
It has a few dependencies, as you might expect, and I also had to patch xml-rpc.el because I'm using Emacs 23 (the author of trac-wiki.el, Shun-ichi GOTO, helpfully pointed me in the right direction), but it's now working beautifully.
It allows you edit wiki pages directly in Emacs, and much more: it's got syntax highlighting, completion of page names, history and diff modes etc., with key bindings and integration for everything you might want.
A few little Python XML-RPC scripts later, and I can convert this post (written in my wiki, using Emacs, of course) into HTML ready for posting on my blog).