Embedding discussion onto a webpage

Dear all,

I have a digg-clone website. However, I want it so that when a user
clicks on a link (which links to another website), it opens up the link
along with embedded discussion (from my website). This is so that a user
can both view the link and also discuss it at the same time.

Are there examples of ways of doing this? I am interested in using Ajax
or Javascript to do this. I do wish there is a more elegant solution
than using frame or iframe.

Thank you,