$text = 'бла-бла-бла :)';
$tr = array(
"А"=>"A","Б"=>"B","В"=>"V","Г"=>"G","Д"=>"D",
"Е"=>"E","Ё"=>"YO","Ж"=>"J","З"=>"Z","И"=>"I",
"Й"=>"Y","К"=>"K","Л"=>"L","М"=>"M","Н"=>"N",
"О"=>"O","П"=>"P","Р"=>"R","С"=>"S","Т"=>"T",
"У"=>"U","Ф"=>"F","Х"=>"H","Ц"=>"C","Ч"=>"CH",
"Ш"=>"SH","Щ"=>"SCH","Ъ"=>"","Ы"=>"YI","Ь"=>"",
"Э"=>"E","Ю"=>"YU","Я"=>"YA","а"=>"a","б"=>"b",
"в"=>"v","г"=>"g","д"=>"d","е"=>"e","ё"=>"yo","ж"=>"j",
"з"=>"z","и"=>"i","й"=>"y","к"=>"k","л"=>"l",
"м"=>"m","н"=>"n","о"=>"o","п"=>"p","р"=>"r",
"с"=>"s","т"=>"t","у"=>"u","ф"=>"f","х"=>"h",
"ц"=>"c","ч"=>"ch","ш"=>"sh","щ"=>"sch","ъ"=>"y",
"ы"=>"y","ь"=>"","э"=>"e","ю"=>"yu","я"=>"ya"
);
$text_tmp = strtr($text,$tr); // в транслит
$text_tmp = preg_replace('/[^A-Za-z0-9_\-]/', '', $text_tmp); // удаляем мусор
$text = strtolower(trim($text_tmp, '-')); // преобразуем в нижний регистр
echo $text;