Gravatars use in posts?

Ok so i found this little plugin called gravatar for wordpress. It looks like it says what it does. makes icons for your guests as the leave comments. What it doesnt say is if it can do this in your own posts as well.

i havent been able to get the plugin working at all yet using this code:

<img src=”<?php gravatar(“R”, 40, “http://www.smrart.org/images/peter.gif&#8221;, “FF0000”); ?>”/>

this was taken off their site and i replaced the fields that were needed. Of course it didnt work, and then when i tried leaving a comment or had a guest leave a comment it also did not work. could someone plz help me out before i have a nervous breakdown.

thanks ( :