Google Reader Toolbar button | How to put a google reader toolbar button in your toolbar

How to put a google reader toolbar button in your browser toolbar.
Google Reader Toolbar button

I have never tried this but see it come of often. How do you put a button for the most read rss feed reader google reader?
Google Reader Tool bar button |

Here is a link to how someone actually built a toolbar button for google reader
http://limitedmage.wordpress.com/2007/06/30/google-toolbar-button-for-google-reader/