This mod is awesome. It adds a really nice minimap which shows light and elevation, and rotates. It has a ton of configuration options and allows you to set waypoints, which show up as a flag on the map, and a directional arrow outside it. If you are like me and hate getting lost or taking circuitous routes because you don't know better, this is a must have.
http://www.minecraftforum.net/viewtopic.php?f=25&t=77497
Download here: http://67.210.100.17/mc/Zan095.exe
PIC OF MOD:
http://i.imgur.com/CeHgW.png