I was reading in the '05 NEC and it talks about bonding connections in 680.26
Quote
(C) Equipotential Bonding Grid. The parts specified in
680.26(B) shall be connected to an equipotential bonding
grid with a solid copper conductor, insulated, covered, or
bare, not smaller than 8 AWG or rigid metal conduit of
brass or other identified corrosion-resistant metal conduit.
Can someone tell me what "rigid metal conduit of
brass or other identified corrosion-resistant metal conduit." is all about?

edited for typos

George Little