And easy: I just dropped a script tag and div onto my page and their system does the rest. I'm using threaded commenting, sorted by time, pre-moderated (I approve all posts before they're live). There's an rss feed for comments somewhere in there too. One thing I like is that they seem to be checking posts/comments against Akismet for spam filtering/blocking.
Downside:
Let's get the js-kit and crush3r.com folks together to mash up something calendar-y... no wait... js-kit & freebase for some semantic widgetation... no wait...
Anyway, it's a fun experiment at least. Drop me a note and we'll give this a spin.