I have had multiple request for my Buffy theme so I finally cleaned up all the mods I add to my themes and made a version of the Buffy theme for WordPress.
It does use category avatars. You can make images and name them after the category id. There is a psd for the avatar and I have included some avatars to start with (which can be changed).
Also I kept the code for the plugin Artiss Social Bookmarks, I use it on all my websites. I have it showing the Facebook, Twitter, Google+ and Tumblr icons. If you don’t want to install the plugin don’t worry the theme checks if it is installed, if not it won’t do anything. You can also remove the code from the loop.php file.
There are 4 widget areas the 2 sidebar columns and then one that spans both columns, and last of all the footer. You can choose to use all, some or none if you wish.