Blocks http://docs.moodle.org/en/Blocks_2.0 an improved feature in Moodle 2.0:
* Blocks are now consistently implemented on every page in Moodle
* No longer any limit to placing blocks in only the left and right column regions but also at the top, center or bottom of areas of pages)
* Any block can be forced to appear in all the page contexts below it (for example, in every course or throughout a course).
* Blocks can placed in the Dock area on the side of the screen (if the theme supports it)
See examples and try it out at http://school.demo.moodle.net Less