Thank you very much!
Here is my contribution for character conversion:
portugues.php
$char_convert = array(
'à' => 'a', 'â' => 'a', 'á' => 'a', 'ã' => 'a',
'ê' => 'e', 'ë' => 'e', 'é' => 'e',
'ô' => 'o', 'ó' => 'o', 'õ' => 'o', 'ö' => 'o',
'ú' => 'u', 'ü' => 'u',
'í' => 'i', 'ç' => 'c', 'ñ' => 'n',
'À' => 'A', 'Â' => 'A', 'Á' => 'A', 'Ã' => 'A',
'Ê' => 'E', 'Ë' => 'E', 'É' => 'E',
'Ô' => 'O', 'Ó' => 'O', 'Õ' => 'O', 'Ö' => 'O',
'Ú' => 'U', 'Ü' => 'U',
'Í' => 'I', 'Ç' => 'C', 'Ñ' => 'N',
'ª' => 'a', 'º' => 'o'
);