I mentioned Newt earlier and ashamed to admit that I did not even think of the great man I supported for Senate last year - Michael Steele.
Let's see...
Dyed-in-the-wool conservative, Catholic, opposes abortion and the death penalty, great speaker, but has never won elective office, probably too "Northeastern" to balance the ticket that way, African-American (which has its pros and cons).
Overall, I think Steele would be a great choice for VP, but probably not so great as a VP candidate on the Guiliani ticket.
"[Steele] has never won elective office"
Michael Steele served as the lieutenant governor of Maryland from 2003-07, and was elected in that capacity.