Google Buzz is pretty cool, and I follow a couple of people who have been developing quite substantial conversation threads in Buzz (particularly Robert Scoble, who asks some good questions and gets a ton of answers).
If you are wondering how to mute a conversation in Buzz (when a post isn’t as interesting to you, for example), you’ve got 2 options:
Click on the far-right top dropdown menu associated with each post and click on the “Mute this post” option.
Press the m key.
This will mute the post and keep it from showing up in your Buzz feed again.
Note you need to have hotkeys enabled for your Gmail account for option 2 to work.