RFC: i18n2ascii(TEXT) stored procedure

I've created the following stored procedure to allow me to do
international-insensitive text searches, e.g. a search for "Resume" would
match the text "Résumé".

I wanted to know:

a) am I missing any characters that need to be converted? My first (and only
language) is English, so I'm in the dark when that is concerned;
b) is there a better and/or faster way of implementing this? I don't want
searches to bog down (at least too badly) as a result of this.

CREATE OR REPLACE FUNCTION i18n2ascii (TEXT) RETURNS TEXT AS '
my ($source) = @_;
$source =~
tr/áàâäéèêëíìîïóòôöúùûüÁÀÂÄÉÈÊËÍÌÎÏÓÒÔÖÚÙÛÜ/aaaaeeeeiiiioooouuuuAAAAEEEEIIIIOOOOUUUU/;
return $source;
' LANGUAGE 'plperl';

--
/* Michael A. Nachbaur <mike(at)nachbaur(dot)com>
* http://nachbaur.com/pgpkey.asc
*/

"Ah, " said Arthur, "this is obviously some strange usage
of the word safe that I wasn't previously aware of. "