IIRC, GeoIP accuracy drops off sharply outside of the US. I did a risk analysis a few years back (I'd post the report, but I don't own the copyright) and we det

IIRC, GeoIP accuracy drops off sharply outside of the US. I did a risk analysis a few years back (I'd post the report, but I don't own the copyright) and we determined that if you get 90% accuracy at the regional level for a country outside of the US, you're doing amazingly well. Contrast that with 99% accuracy at the regional level and 90% accuracy at the city level within the US. Yahoo used to have a GeoIP developer API, but I believe they deprecated it. You could check their developer API index.