The WordPress PageRank Widget Plugin allows you to display a PageRank badge as a widget. It is much more convenient than having modify your templates to include such a badge. It can be used either at a page/post level, or a top site level.
There is also a feature where you can place the badge within a pagepost to display the PageRank for that particular page/post, if you so desire.
For more information, visit the plugin homepage at: