in your bootstrap class:

class Bootstrap extends Zend_Application_Bootstrap_Bootstrap
{
//set a Log resource
public function _initLog()
{
$logger = new Zend_Log();
$logger->addWriter(new Zend_Log_Writer_Firebug());
return $logger;
}
}

Now you can call the resource (Log) from anywhere in you're controllers

$logger = $this->getInvokeArg('bootstrap')->getResource('Log');

or from in a model (or elsewhere)

$logger = Zend_Controller_Front::getInstance()->getParam('bootstrap')->getResource('Log');

You said "Place this in your bootstrap file before dispatching your front controller"
and "… to log something to Firebug just use it in your model, view, or controller.."

You can easilyy access bootstrap object in controller how are you accessing $logger instance in model ?