Yaki is a Wiki/Blogging platform with some really nice features. The main one is that it is extremely light weight. Pages and posts are simple files, with a set of headers at the top that define the details (tags, dates, etc). Mirroring and backups of the site can then be done with any file synchronisation tool.

I toyed with using it on this site, since I wanted to add Wiki-Style behaviour, but ended up using my old favourite for more complex sites, Drupal.