If you have enabled Gmail’s keyboard shortcuts, then you are set to go with Google Buzz’s shortcuts as well. As with Gmail, Buzz’s shortcuts allow you great functionality without having to rely on your mouse.
m – mute a post
j – move to the next share
k – move to the previous share
Shift + L – like a message
r – add a comment
p – go to newer conversation
n – go to older conversation
o – expand conversation
Also, you can access Buzz from any view in Gmail by typing g and then b on your keyboard.