There is a few improvements I want to suggest for this mod:
1. Add possibility to create parents for Locations as there is in Categories. For example:
1.1. Add feature to search either from parent-locations (I want to see all ads that are in selected state) or child-locations (I want to see only ads that are in selected city).
2. In acp: Possibility to add custom fields (text-fields + database-based fields (as locations)).
2.1. Add function to select if this field (database-based fields only) is added to search fields or not.
Otherwise, keep up the good work!