Basic information that, on reflection, would have been useful:
The machine is a Linux machine running Apache w/MySQL... The usual poor mans super-server.

As is my understanding, replication very specifically only works in one direction, master -> slave, and there's a very good reason for this. I'm hoping to perhaps argue him away from this model.
And, (unfortunately|fortunately), this man also happens to be very famaliar with databases, of many different brands.

His notion is for, I suppose, some form of physical security on data - credit card numbers may be stored in the database and he doesn't want the second, "Customer management", server to be able to ever know this information exists...
While I appreciate his paranoia in protecting his customers, the server that he has for his current inelegant management system runs SSH, qmail and Apache... Not what I would usually consider high-risk software packages. With this very limited opportunities for black-hat access, I see the data as being somewhat secure.

But of course, maybe thats why he worked at the PKI company and I never will?

JP,
-- Alexander Widdlemouse undid his bellybutton and his bum dropped off --