JS Kit - comments widget for any web page

I recently tried out JS Kit on an online magazine for which I help out. You only need to put one SCRIPT tag and a DIV tag to instantly enable comments on that web page, within that DIV. To distinguish b/w comments on different pages or articles, you can add a "path" attribute to the DIV with some unique value.

They block spam too. You can add your own custom fields to the comment, apart from the usual name, e-mail etc. There is support for threads, with e-mail notification of replies (The site admin gets an e-mail for every comment).

One issue is that the mail notification misses all query parameters in the link to the original article. The customization UI on their site can do with a face lift too.