Finding the location of the browser client.
- Identify the IP adress of the HTTP request.
- Look up the IP address f.ex. throught a database from http://www.maxmind.com/
- Look up the reverse DNS address from the IP address. This is not very exact, and can easily be faked.
- Look up the IP in the allocated ranges. Start at http://www.iana.org/numbers/
- Ask the client broser to find the current location. This usually requires the user to accept. The location can usually be much more exact, especially if the device has a built-in GPS.