Question : SBS 2003 BACKUP DC

would it be possible to implement a backup dc in a SBS 2003 environment?
if so, how would i go about this?
i have searched and found indirect answers to this, that only one sbs 2003 server can exist in its domain.
but what would happen if it went down, surely there is an option

Answer : SBS 2003 BACKUP DC

Small Business Server is only meant to exist in a single DC domain. No other DC's can exist. That's the limitation of the product and why it's cheaper than the full blown OS.