use the search for "additional user field", there was a large thread somewhere ... use "user_ip" as your new userfield. After you've done that open your register.php,
and find:
if (!$error) {
$additional_field_sql = "";
$additional_value_sql = "";
if (!empty($additional_user_fields)) {
$table_fields = $site_db->get_table_fields(USERS_TABLE);
foreach ($additional_user_fields as $key => $val) {
if (isset($HTTP_POST_VARS[$key]) && isset($table_fields[$key])) {
$additional_field_sql .= ", $key";
$additional_value_sql .= ", '".un_htmlspecialchars(trim($HTTP_POST_VARS[$key]))."'";
}
}
}
right after add:
// IP Logging of new user
$user_ip = $site_sess->user_ip;
$additional_field_sql .= ", user_ip";
$additional_value_sql .= ", '$user_ip'";
save it, and you should see the IP in the admin area under "edit user" (if you followed the thread for the add. user field)