While answering a question in the wordpress forums, I remembered an (obscure to me) function in php which generates a regular expressions ( regex ) to be used in a MySql query. This is very useful when performing a dynamic ORDER_BY or a SELECT and you do not want to use the LIKE statement. The syntax is as follows:
$new_string = mysql_regcase($string);
Where the $string was the original query string and the $new_string is the regex for that query string. I am not sure whether WordPress uses this or not. However, it sure could prove useful in unlikely circumstances.