I have seen “Buzz this” button on many websites. They are not actually buzzing that post to Google Buzz. If you want to use that kind of Buzz buttons you will have to
1. Set up a Google reader account
2. Add Google Reader to your Connected Websites in your Google Buzz
Now when you click the Buzz button that will create a Shared link in your Google reader and which will automatically come into your Buzz.
If you are a BlogEngine.NET user and you need to add that kind of link to your blog you can copy and paste the following code in to your PostView.ascx page of your theme
<a href="http://www.google.com/reader/link?url=<%=Post.AbsoluteLink %>&title=<%=Post.Title %>&srcURL=<%=Post.AbsoluteLink %>" target="_blank" rel="nofollow external">
<img src="http://img2.pict.com/15/da/3e/2809374/0/googlebuzz.png" width="50" height="58" alt="" /></a>
This button will add a Buzz this button for all the posts for BlogEngine.net blog posts.