I have now jumped the band-wagon and have installed a wiki. This particular wiki serves a particular purpose and a particular enclosed circle of people, who are working with me in a collaborative writing process. Hence, I have password protected the wiki, and will only give access to selected participants (only qualified enterprise architects need apply).
I was shopping around for a good wiki software package. I ended up with TWiki, which so far has been great. Twiki is open source, Perl-based, and runs fine on a virtual host. It also has cool add-ons and plugins, such as the MovableTypePlugin (for blog-wikis, blikis, I suppose) and the ActionTrackerPlugin, which may be handy as a project manager’s tool.