Fire Hydrant Inventory

I'm working on a really interesting project right now that spun out of the mapping options in the Staff web interface for ZP SQL. I have a customer who wanted to know if we could add a database for fire hydrants and then map those as well. The prototype pages are in testing right now but the site allows you to enter any address and then shows a map of the closest fire hydrants to that property. The fire hydrant database contains Latitude and Longitude fields just like our property database does. In this case though, the customer has to supply the values for those fields because we can't geocode them the way we can an address. Fortunately, inexpensive GPS units make it fairly easy to construct your own database of positional coordinates. One of the bits of code I had to develop for this exercise is a way to determine distance between two geocoded points. This is used to find the nearest fire hydrants in this site but will be very useful for distance calculations in other web-based scenarios too.