Custom Comment Header

I want to provide some additional items above where my comments are input. I’d like to have a custom social bookmarking column next to a tag cloud / related articles column.

This site has what I’m looking for…

http://www.fourhourworkweek.com/blog/2010/05/18/tim-ferriss-scam-practical-tactics-for-dealing-with-haters/

Is there a plug-in to do this or how do I go about modifying the code?

Thanks!