I refactored quite a bit of the user.module:

$ diffstat user.patch
database/database.mysql |    4
database/database.pgsql |    2
database/updates.inc    |   10 -
modules/block.module    |   20 +-
modules/locale.module   |    9
modules/profile.module  |  108 +++++++----
modules/system.module   |    8
modules/user.module     |  456 +++++++++++++++++++-----------------------------
8 files changed, 289 insertions(+), 328 deletions(-)

More functionality, less code.  Here is a list of the changes:

- Some user API changes:
   + When $type is 'form', you have to return an associative array of groups.  In turn, each group is an array with a 'title', 'data' and 'weight'.
   + A new $type has been added, namely 'categories'.  User settings can be organized in categories.  Categories can be sorted, as can the groups within a category.  (Ordering 'categories' is somewhat broken due to a bug in the menu system.)

- The 'my account > edit' page will use subtabs for each 'category'.  Read: you can break down the account settings into multiple subpages.

- Profile module improvements:
   + Added support for private fields to the profile module!
   + Improved workflow of profile administration pages.
   + Improved the form descriptions.

- Code improvements:
   + Unified user_edit() and user_admin_edit().
   + Unified and cleaned up the validation code.  Fixed some validation glitches too.

1 files changed, 4 insertions, 4 deletions

diff --git a/modules/system/system.module b/modules/system/system.module
index e010c27bd..5fccde31e 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -94,14 +94,14 @@ function system_menu() {
  *
  * Allows users to individually set their theme and time zone.
  */
-function system_user($type, $edit, &$user) {
-  if ($type == 'form') {
+function system_user($type, $edit, &$user, $category = NULL) {
+  if ($type == 'form' && $category == 'account') {
     $options = '<option value="">'. t('Default theme') ."</option>\n";
     if (count($themes = list_themes()) > 1) {
       foreach ($themes as $key => $value) {
         $options .= "<option value=\"$key\"". (($edit['theme'] == $key) ? ' selected="selected"' : '') .">$key - $value->description</option>\n";
       }
-      $data[t('Theme settings')] = form_item(t('Theme'), "<select name=\"edit[theme]\">$options</select>", t('Selecting a different theme will change the look and feel of the site.'));
+      $data[] = array('title' => t('Theme settings'), 'data' => form_item(t('Theme'), "<select name=\"edit[theme]\">$options</select>", t('Selecting a different theme will change the look and feel of the site.')), 'weight' => 2);
     }
 
     if (!variable_get('sitewide_timezone', 0)) {
@@ -111,7 +111,7 @@ function system_user($type, $edit, &$user) {
         $zone = $offset * 3600;
         $zones[$zone] = format_date($timestamp, 'custom', variable_get('date_format_long', 'l, F j, Y - H:i') . ' O', $zone);
       }
-      $data[t('Locale settings')] = form_select(t('Time zone'), 'timezone', $edit['timezone'], $zones, t('Select what time you currently have and your time zone settings will be set appropriately.'));
+      $data[] = array('title' => t('Locale settings'), 'data' => form_select(t('Time zone'), 'timezone', $edit['timezone'], $zones, t('Select what time you currently have and your time zone settings will be set appropriately.')), 'weight' => 2);
     }
     return $data;
   }