My favorite way to implement and simply/safely self host a web comment system is to log all POSTs that include a string like, /@say/ in the URL to a unique log file on disk. This txt file is then the comments and included via server side includes for minimal attack surface with just enough features to do what's needed. This means you have to actually control the webserver but in this context I think that's reasonable.
Before I clicked the post I thought it was your system. Don't know if I can call your comment system "cheapskate" though, but I already told you I like it!
