> You do not want to put two ethernet cards onto the same ethernet cable
> for performance reasons -- it actually lowers performance because
> (theoretically) it increases collisions.

If you connected 2+ ethernet cards to a switching hub, you would be
able to have multiple clients talking to your server at the
same time.  I'm not sure how 'load-balancing' would occur, but
I would think having the same ethernet address would definitely
problem.. :-)

-Andrew