yes indeed, but it uses PCRE (perl compatible regular expressions), not ereg.
http://samuelfullman.com/team/php/tools/regular_expression_test_p.php
With this you can test your regular expressions on any page on the internet. Just make sure to use the full url:
http://amazon.com/
and not amazon.com.
Email me if you have feedback or questions, and feel free to tell your friends.
Sam Fullman
Compass Point Media