"Why not ikiwiki? Actively maintained, lots of plugins and works as a blog engine so you don't have to use blogger.com ;)"
My answer was simple: it hadn't shown up in searches I'd done. I probably share some of the blame for that, but it also highlights that as a F/OSS project getting the word out and making sure you are prominent, particularly for common search queries, is important. In this case, I missed ikiwiki, but Richard made sure that didn't last long. ;)
I managed to find some time at the end of a long day yesterday to toy with ikiwiki and since I had spent time writing about how great gitit is (it really is! :), I figured it would be nice and fair to at least try ikiwki and report back.
Here is my verdict in summary: it's an excellent tool, far more capable of gitit, but also comes with a lot more overhead in terms of setup and management. It is a classic trade off between power and ease of use.
ikiwki requires an investment in time to set up. If you are running Debian, there are packages for it, otherwise you'll be installing lots of perl modules (thank goodness for CPAN!) and reading the not-as-coherent-as-it-could-be documentation on getting it set up. I felt a little like I was building Plasma Desktop from scratch at times with all the dependencies. ;)
Once ikiwki is set up, you next need to ensure the webserver is set up properly. Unlike gitit, ikiwiki does not provide it's own web server, which is not a bad thing. It just means it's one more bit of software to configure. Thankfully, other than a missing ExecCGI directive, openSUSE's apache2 install is perfectly set up to host ikiwkis in your home directory.
Then there is the configuration. Richard was right, ikiwiki has tons of plugins. Which means choosing which to enable and which not to, and how to configure the ones you do enable that have configuration options. Thankfully the setup page is available via the web interface itself, though the configurations options are often rather cryptic. I wasn't sure what some of the things did, but with some experimenting I figured it out. (Flashbacks to KDE software from the KDE2 or 3 days. :) One thing to keep in mind when trying out ikiwiki is that it looks horrible by default, but if you just put "actiontabs" in for the theme plugin configuration it looks far more sensible.
For the investment of time you get a wiki with full text searching, caching, templates, tags, link tracking and all sorts of other goodies. It does have it's flaws: the management UI is nothing to write home about, the permission management is primitive and the documentation could use some help. ikiwki stores the pages in markdown, but doesn't seem to provide conversion utilities to other formats (other than HTML, of course), but you can easily use pandoc for that.
However, with ikiwiki you do get a very capable, light-weight wiki suitable for group editing and all backed by git for easy replication and interaction behind the web interface, and that could well be the killer feature for ikiwiki: a git backend with lots of features on top.
So now I have not one but two great tools to choose from: gitit when I need something fast to set up and easy to use, and ikiwki when I need something with more features. Got to love Free software. :)