Firewall Rules by MAC Address. IS it possible?

From:	GD Incorporation <rbasuki at gdincorporation dot com>
To:	<m0n0wall at lists dot m0n0 dot ch>
Subject:	Firewall Rules by MAC Address. IS it possible?
Date:	Wed, 29 Sep 2010 13:41:01 +0700

Hi Guys
 
Can we filter user by m0n0wall using his MAC Address? Because the IP address
is dynamic. I need to give access to one single user all internet access
except port 80. In other words we want to prevent user from using browser to
browse internet, but we wouls like to give him access to remote desktop and
yahoo messenger etc.
 
Thank you
Rendra