OpenStreetMap places less then 2000 meters apart with names of the same length:
select p1.name, p2.name, p1.osm_id, p2.osm_id, p1.place, p2.place, distance(p1.way, p2.way) from planet_osm_point p1, planet_osm_point p2 where p1.place !='' and p2.place!='' and p1.osm_id != p2.osm_id and distance(p1.way, p2.way) < 2000 and octet_length(p1.name) = octet_length(p2.name) order by p1.name;