Discover users location?

[iblair]

Is it possible to discover a web users location when they connect to your site? I would like to use different advertising options based on whether they come from US or UK. I think ebay does something similar when you first connect, but do they use some kind of expensive router to do this, or a nice little bit of javascript?

Many thanks,
Ian

[Fang]

This is on blocking specific countries, but the principle is the same.
http://www.webdeveloper.com/forum/showthread.php?t=133633

[iblair]

Thanks Fang! Just what I need!