Question: How can you use the JQuery Auto-Completion plugin to suggest a location ("City, State") for an input field?
Meaning, someone wants to type in "Chicago, IL" ... so they begin typing "Chi" and it auto-suggestions "Chicago, IL".
My biggest hurdles is finding a service that I can query to find out all US city+state names.
I essentially want to do what the StackOverflow "Tags" input form works but form "City, State" auto completion.
You either need to make an ajax call to the server whenever a key is pressed to update the "auto complete" drop down, or include an array of all the possible "city-state" strings and filter them when a key is pressed.
You can download a free CSV that contains cities and states at: http://www.maxmind.com/app/geolitecity
You will have to create your own database, but with this information, you will be able to query the info you need.
There's a group called GeoNames that offers both downloadable databases and free webservices to obtain this type of data. For example, the search
http://ws.geonames.org/searchJSON?name_startsWith=Chic&country=US
will return a bunch of JSON that includes Chicago, IL (JSON properties include, among others, "name":"Chicago" and "adminCode1":"IL").
Based on user information above, I was able to locate the following JQuery Geoname integration demo