Is there something like ipython for PHP? Syntax highlighting and not having the console exit to shell on the first exception would be nice to haves. :)
Never tried, but http://david.acz.org/phpa/ sounded promising. The page also lists two alternatives which might be worth to investigate. There were also some musings that the builtin php -a was refurbished in php-trunk/5.4. So maybe try the SVN version (at least it supports non-ASCII input).