Custom geolocation API/database

I’m finding the MaxMind GeoIP database used by Piwik to be rather inaccurate and would like to replace it with EurekAPI API calls which seems better. How could I go about doing this? Is there anywhere I can hook up a call in the source to override the geolocation look up?

You would have to extend the tracker via a custom plugin. Here you should be able to find some examples.