Could you buzz a little Buzz for me… Hmmm… maybe not  
Google’ Buzz is powerful but I think Google’s tight integration with Gmail was a poor decision. To be clear, I am not against integrating it with Gmail - in my opinion that is what makes Buzz so much more powerful. What I dislike is the poorly explained service and its default tight integration with Google’s services and profile; but even worse is the utter lack of simple and clear controls on how far Buzz can assimilate into our personal fabric of online life (albeit Google-powered i.e. Gmail, Picasa, YouTube, search, Chromse bookmarks, Google Docs, Voice, GReader… need I go on?). Google is undoubtedly aware of its tremendous value to so many users because it, well just works so well, and it costs nothing. So should they not have considered our potential concerns before they integrated Buzz so tightly? Personally, I think they did but an engineering mindset drove their product requirements. Sadly the end result is very much like Apple’s trust-us-we-know-this-is-the-right-way attitude (which is getting no attention due to its current success, but thats another discussion).
Learn about Buzz and how to use it smartly from the links below (note: articles are listed in oldest-to-newest order; read them all before taking any action).
http://lifehacker.com/5470104/google-updates-explains-buzz-privacy-setup
http://lifehacker.com/5470513/how-buzz-exposes-private-email-addresses-in-replies
http://lifehacker.com/5471122/how-a-simple-url-hack-can-expose-your-gmail-address
http://lifehacker.com/5470671/top-10-google-settings-you-should-know-about?skyline=true&s=i