Do a write in for your primaries and have a brokered convention.I'm with you as far as the brokered convention, but there's another way to get there besides a write-in campaign, and that's by spreading the delegates around among various candidates. Since Mitt is presently the leader and seems likely to gain the most from Fred's having dropped out, that means voting for a candidate other than Mitt who has a real shot at denying him a particular state's delegates but no shot at all of winning the delegates needed to secure the nomination prior to the convention.
In my state, New York, that would mean Rudy.
That also sounds like a plan and could work.