Commentful has been acquired by blogflux, so the new address of commentful is at http://commentful.blogflux.com. If you are hearing first time about commentful, it is a service that tracks blog posts and notifies you whenever a new comment has been added to that particular page. I have blogged about it here.
Apparently the new Commentful is faster, supports more sites, and is on much more powerful servers. Everything has been re-written from the groundup, focusing on speed and reliability.
http://commentful.blogflux.com
Wow! Thanks for the info. I have been checking CF site and it has been unavailable. Know I know the reason. Thanks. It is really a very good and helpful service.
PS: nice anti spam words :)