Tracking country of visitors

What is the most accurate way to know where they come from?

[Bobby]

Up to now I have used a tracking service which gives me an idea based on time zone but no hard evidence on country my visitors are coming from, does anybody have a recommendation?

The service I use lists some countries, but since a lot of people have static IP addresses I don't really know their country of origin.

[mipapage]

I nknow how you can build your own with PHP, do you have that available?

[Bobby]

Yes, do you have a script or could you let me know how to implement it?

[mipapage]

I've been meaning to write one for awhile now, but haven't had a minute of free time...

I saw one here:
ht*p://www.pierzchala.com/visitor-tracking.html

I believe that he wrote it in perl, but offers hints for writing it in PHP...