The amount of data out there via API's is increadible these days. For instance you can take an address, and get the latitude and longitude using Google's GeoCoding API.
I am using this API along with some others to build a pretty some interesting stuff (more on that when its public).
Today I needed to calculate the distance between two points, I found a bunch of formulas here to convert two lats and longs into miles. They had some more complicated formulas, but I went with an easier one because approximate accuracy was sufficent. Here's how the formula translated into SQL (tested on MySQL):
SELECT id, place_name, ROUND( SQRT( POW((69.1 * (#Val(arguments.latitude)# - latitude)), 2) + POW((53 * (#Val(arguments.longitude)# -[Read more...]