Correlation between visitor's physical location and IP address

Hello all I am currently working on a project where prices in 2 currencies must be displayed on a web site. Web visitors from Europe should be shown the price in Euro and those outside Europe should be shown the price in US Dollars. Due to a whole list of 'political' problems, the European customers should not be able to see the USD prices and the non-EU customers should not be able to see the USD prices. I know that sucks, but that is the way it is. I cannot change it, unfortunately. All price data is stored in a mySQL database and PHP4 is to be used to get this data into the HTML. ;-) The question is: How can one ascertain the physical location of a web visitors' computer when he/she comes to the web site? Is there a correlation between IP addresses and countries? If there is, where can one find a table illustrating this information? Has anyone attempted something like this? Two examples come to mind where a similar solution is in operation: 1. www.altavista.com : when I go to www.altavista.com I sometimes get a pop up window in German telling me that there also exists Altavista in German. The message is in German. Some how Altavista knows that I am in Germany. 2. www.imdb.com : when I look at the details of any movie, I see a link to amazon.de to buy that movie. I can hardly think that anyone outside Germany would get that link. Somehow these two sites 'know' where I am physically located. Now, how do they do that? If anyone can help me, I would LOVE to here from you! /S _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.