Sticky blocks
From MoodleDocs
Moodle1.6
Sticky blocks can be accessed from the admin page. It is a method of forcing a block to appear site-wide. They can be configured for courses and/or MyMoodle pages.
If you add a block which is already present in a particular course of MyMoodle page then it will result in a duplicate. The sticky block will be non-editable whilst the duplicate will still be.