If memory serves me right, Dennis Hoshield wrote:
> I thought I have seen this in the lists before, but haven't found it again,
> now that I'm looking to implement it....
> 
> Can multiple interfaces be bridges to a single interface?  i.e. wireless to
> a single WAN?

The m0n0wall UI doesn't support configuring a bridge this way, but the
FreeBSD bridging code underneath does.  For more details, see:

http://www.freebsd.org/cgi/man.cgi?query=bridge&apropos=0&sektion=4&manpath=FreeBSD+4.10-RELEASE&format=html

In m0n0wall's view of the world, each "group" of bridged interfaces
contains exactly two interfaces, and exactly one of the two has an IP
address assigned to it.  You might be able to tweak the bridging
parameters underneath the UI to make it do what you want.  Maybe.  You
could also shoot yourself in the foot pretty well.  :-)

Bruce.