I recently wrote a conversion script and PHP wrapper so that the data from the Perl "last-chance transliterator" Text::Unidecode by Sean M. Burke can be used from PHP: unidecode_php-0.3.tar.gz. To use this you'll need to install the Perl Text::Unidecode module and then run the udec2bin.pl script inside the unidecode_php package.
Example PHP usage ( Read more... )