I found this over on Titus' blog (http://titusferguson.wordpress.com/) and it looks like a cool service. I'm going to give it a try.

I'd rather wait for the Clipmarks community to continue to grow than seek out others to share with on another site. Clipmarks does what I want. Why mess with more?

The service is supposed to be able to bring all the comments you have made on people blogs ans other sites to one place and make them manageable. I guess you could clip the blog post and comment from there but then all the traffic is off the site that started it.