The CoComment service, which was debuted this year, has some updates, which make this service actually useful. Before those updates there was no way to check for and be notified about comments posted to somebody's post. Now it is possible!
For example: you noticed some interesting post, but don't want to participate in the comments. But you still want to look at other people's thoughts. The only option would be to bookmark the post and come back later. In many cases you will just forget about returning back and the discussions will be gone.
Now you just instruct CoComment's crawler to report any comments and it, if you have any luck, will.