I've posted the first beta of PHP Internationalization extension, bringing support for some ICU functions to PHP. Documentation can be read in PHP manual, and the downloads are available on PECL site.

His goal is to have it all ready and waiting (and included) for when PHP 5.3 is set to roll off the line. The extensions consists of four major parts that do the work for you - the collator, number formatter, normalizer and a locale component.