If you don't need much fancy functionality you might could wrangle something like Kwiki or Blosxom into behaving the way you want. I set up the later to track project status and todo items at work with a few custom plugins and a convenience script that hides some of the paths involved (i.e. projects are categories and you say you want to add a new status entry for project foo; the wrapper then starts:
$EDITOR /bloxsomroot/foo/foo_status_datestamp.txt for you).