Locate nearest major city

I'm working on a website that allows users to find our nearest Motel location (There are 26 of them across the US). I have a list of cities where they are located at.

I want to display the nearest location when a user goes on our front page. For example if a user comes from Newark, NJ, he will be shown images from our NYC motel and if a user comes from San Jose, CA he will be shown San Francisco images.

What's the best way to do this? Does anyone know any examples out there on the web that shows what I'm trying to do? Is this even possible?

I sa开发者_开发知识库w Groupon and LivingSocial using this so I thought why dont I give it a shot. :)

If you're using apache, you can give geoip a try.

http://www.maxmind.com/app/mod_geoip

You'd first need to store the latitude/longitude coordinates of your motels in a database - use google maps, it won't take too long with 26.

Then get the visitor location, using something like IP2Location - http://www.ip2location.com/developers.aspx

Then calculate the distance between the visitor and each of your motels - http://sebastian-bauer.ws/en/2010/12/12/geo-koordinaten-mysql-funktion-zur-berechnung-des-abstands.html (it is in English...)

You could give Geolite city a try. It is free (with an attribution clause) or can alternatively be bought. That reduces the "find closest city to user's IP address" problem to "find the closest city to a known city".

The same company offers a city database, which among other things contains longitude/latitude. That should do the trick.

You can get the nearest city to an IP address using the free data on MaxMind.com (I beleive you can pay for more accurate databases). If you can get the lat/long for the city and compare it to the lat/long for each of your motels you win :)

What you want is to store the lat/lng coordinates of the motels and then let the user type his location into the browser most likely a zipcode and then you want to use the harvesine formule to calc the distance between the user and the motel to display nearby motels. Or you can use a IP to geo coordinate service like IP2location to get the users location.

I used this code to calculate distance of a googlemaps latitude and longitude from a table of addresses.

Geocode was a function that returned an array of latitude and longitude from google maps api given an address string, in the case below a zip. The table of your locations would have to include lat and lng columns. In this example i used decimal(8,5) types but you could also use a point column type.

$starting_location = geocode($zip);
$distance = '(3959 * acos(cos(radians('.$starting_location['latitude'].')) * cos(radians(lat)) * cos(radians(lng) - radians('.$starting_location['longitude'].')) + sin(radians('.$starting_location['latitude'].')) * sin(radians(lat))))';
$location_row = query('SELECT location_id,addr,addr2,city,state,zip,phonenumber,'.$distance.' AS distance FROM location_info WHERE '.$distance.' is not null ORDER BY distance LIMIT 1');

Correct me if I am linking to another's answer incorrectly, but I think I got my direction from this question: Fastest Way to Find Distance Between Two Lat/Long Points