Has Google Buzz had its 15 minutes of fame or what? I’m not going to explain how you can avoid showing the entire planet all of your contacts–there are a thousand other sites where you can find that info–but I did find this list of undocumented little tips for Google Buzz interesting: Post from SMS? Buzz-it widget? Geolocation for Buzz? Turning Buzz off? Nice list. Honestly though, I am still not 100% convinced that this will be a service that Google keeps its range of offerings over the long-term.
The problem with duplicating functionality that has similar established sources on the web is that even if you are Google, if enough people do not participate to stimulate a Network Effect, a tool like Google Buzz can have limited utility.

