I have just integrated http://ipinfodb.com/ as one of available geo IP providers. So we have four possible geo IP providers.

• mod_geoip2 - if you are running vps i recommend to use this. It's local solution and it's the fastest and the most stable way.
• http://ipinfodb.com/ - new one, just integrated. You will have to regsitere to obtain API key
• http://freegeoip.net/ - free option, not requiring any registrations. But our server got IP ban, so on demo I'm using mode_geoip2 option.
• http://www.locatorhq.com/ip-to-location-api/index.php - not sure does is still works. :)

If you have any other reliable GEO IP provider let me know in comments :)