@WrathofGod: It is to aid in finding absolute North, South, East, or West (this is how walljumping is accomplished.)
Here's the code (and don't give me +rep for it, all I did was copy and paste from another thread floating around on here.)
Code:
/run local p,f,m,t=Minimap,CreateFrame"Frame"m,t=({p:GetChildren()})[49],p:CreateFontString(0,0,"SystemFont")t:SetPoint("TOP",0,-9)f:SetScript("OnUpdate",function()p=m:GetFacing()/PI%.5;t:SetText(format("124cff%02xbb00%.3f",255*(1-abs(4*p-1)^92),p))end)
Basically, when this macro is activated it will create a number at the top of your minimap, like 0.485 or whatnot. You want to get as close to 0.000 as possible, and the number will be green when you are close or right on it. When you are on 0.000 or very close, you can then most likely do a successful walljump.
If 0.000 isn't available, the next best ones are 0.500 or 0.001, but sometimes a successful walljump can be done anywhere from 0.586 to 0.004 depending on the wall.