At work I’m starting to experiment with some really cool GIS and starting to hook their data into useful applications. Hopefully I’ll get them out the door soon so I can show them off publicly. 
Anyway, the lesson learned today is that points in GIS are not exactly the same as a point in math.
Math:
x,y
GIS:
lat, long
The problem is, latitude is actually a Y coordinate. Latitude refers to a point relative to the equator. Longitude is actually an X coordinate, since it is referring to a point relative to the Prime Meridian.
Moral of the story: when you’re reading a database of X, Y points on a map in decimal degrees to plug into Google Maps, you don’t want to plug them into the GLatLong function in that order. In other words, don’t use GLatLong(x,y) … it’s wrong. Use GLatLong(y,x).
