I've been working on a perl module that displays messages in the
FirePHP console and bindings for the Catalyst logging universe.
The only thing you need to do to start using FirePHP is to include
Catalyst::Plugin::FirePHP in your plugin list. Everything else should
happen automatically, no other config should be needed (at least when
using C::Log or C::Log::Log4perl).
The current (quite usable) implementation can be found at
http://github.com/willert/firephp-perl/ . I'd like to invite you to
test, break, criticize to your heart's content.
 FirePHP enables you to log to your Firebug Console using a simple
PHP. All data is sent via response headers and will not interfere with
the content on your page. (taken from http://www.firephp.org/)