Rei's minimap

Rei's Minimap is a very helpful mod. It creates a minimap in the corner of the screen of your surrounding area.
NO it does not map caves or show any area below the surface. NO that feature will not be activated. If you really feel a need for it, lobby the Terraferma gods for a good ol' fashion junk punch.

http://www.minecraftforum.net/topic/482147-11100-jan14-reis-minimap-v30-01/

and don't forget to get mod loader:
http://www.minecraftforum.net/topic/75440-v11-risugamis-mods-everything-updated/

The minimap and modloader can be installed very easily using MCpatchers Mod's installation.