I'm looking for a (fast) way to tell the region/city of an IP address and came across MaxMind Geolocation http://maxmind.com .
They have a free version and a commercial version. I was wondering if anyone had used it, or had alternative suggestions.
One interesting thing is that they require that you install some C library to query a downloadable binary which contains the IP block data. They also provide APIs in all the popular languages. The queries seem fast...looks like you can look up ~hundreds per second which is what I need...
We are not in the US and were looking for a service that could provide geolocation to a more detailed level than city, preferably postcodes. We have not found a service that could do this for us as accurately as we were hoping.
But if you're in the US and/or just looking to resolve IPs to cities, then both IP2Location and MaxMind seem like they'd be worth looking into. Both companies were quite responsive to email contact.