Change title of location_cck fields

hmmm. Theme or form_alter?

try looking at issues tagged with:
location theming
or
location theme edit form

Note that this code is created for the 3.1 version or current dev.

The location module provides a hook for this, called hook_locationapi(&$obj, $op, $a3 = NULL, $a4 = NULL, $a5 = NULL)
The field_expand $op is where locations fields are created and you can use that to modify the different fields of a location.

Here is an example that sets the title of the city field to Area:

<?php
/**
 * Implementation of hook_locationapi().
 */
function token_locationapi(&$obj, $op, $a3 = NULL, $a4 = NULL, $a5 = NULL) {
  switch ($op) {
    case 'field_expand':
      // For the field_expand $op, $a3 is the field name.
      switch ($a3) {
        case 'city':
          // This will be array_merged in with the field definition.
          return array(
            '#title' => t('Area'),
          );
      }
      break;
  }
}
?>

You need to create a custom module and add this hook.

use string override module

This does not work in Drupal 7 unless I am missing something

function chris_locationapi(&$obj, $op, $a3=NULL, $a4 = NULL, $a5 = NULL) {
  switch ($op) {
    case 'field_expand':
      // For the field_expand $op, $a3 is the field name.
      switch ($a3) {
        case 'name':
          // This will be array_merged in with the field definition.
          return array(
            '#title' => t('Building Name'),
            '#description' => 'If you know the name of the building, enter it here.',
          );
      }
	 case 'additional':
          // This will be array_merged in with the field definition.
          return array(
            '#title' => t('Room Number'),
            '#description' => 'If you know the room number, enter it here.',
          );
	case 'street':
         // This will be array_merged in with the field definition.
          return array(
            '#title' => t('Street Address'),
            '#description' => 'If you know the street address, enter it here.',
          );
      break;
  }
}

have you checked the Weight of your module ?

Mine begins with an F so it is executed before the module location.

Thanks Rooby for the tip btw.