I'm not sure I want to invest time to figure out yet another internet tool (I only JUST bit the bullet and started tweeting), but it does look interesting. A couple of links:
1) How to Do Everything in Google Buzz (Including Turn It Off)
& more importantly,
2) Warning: Google Buzz Has A Huge Privacy Flaw
Not all will find the issues laid out in the latter article problematic, but for those who do NOT want the entire internet to know who they talk to most (for personal or professional reasons), the article is most definitely worth a read.
In short: when Buzz pops up in your GMail (which for me it did without asking) it automatically starts following your most contacted email addresses, which are then publicly displayed on your Buzz profile. It is possible to make that part of your Buzz profile private; the article tells you how.
eta; Grr. I removed all sites from Buzz, including Google Reader because well, I get all of that in Google Reader. I saved, Buzz said, "0 connected sites". Until the next refresh, that is. Huff! Anyone know if that's a bug, or am I doing it wrong..?