here's what I did.

edit the template item.php. Add this under the technochrati one.

<li><a class="googlebuzz" title="<?php echo JText::_("Add to GoogleBuzz"); ?>" href="http://www.google.com/reader/link?url=<?php echo $this->item->socialLink; ?>&amp;title=<?php echo urlencode($this->item->title); ?>" target="_blank"><span><?php echo JText::_("Add to Google Buzz"); ?></span></a></li>

Edit the k2.css 
	a.googlebuzz {background-image: url(../images/social/googlebuzz.png);}

Upload the icon.

Edit the language file.