I have just been playing with a javascript tool for identifying the “geolocation” of the visitors to your site. 

Firstly you have to register with the site to create an account before you can get the script to place on your site. 

Once you have the script on the site it provides you with a map or globe  which identifies the location of all those people logged into the site or who have logged on in the last 24 hrs.

The site works by using the IP address of the visitor.  This process is reliable 97 %  of the time for the country of the visitor and 75 %  for its city or its region.

Have a look at the service at Geovisite.com