Originally Posted by Mongolmike
I think raising your non-hitting hand is also an acceptable way to send a message.
This. Obviously no need to raise your hand if you're still walking to the receiving position, but if you are in position but not yet ready for whatever reason (adjusting feet, something in eye, whatever), just raise your hand until you are ready.
Then again I have limited experience with quick servers. I can't remember anyone attempting this against me on a first serve. There is one guy I know who will sometimes hit a second serve alsmost immediately after first serve fault to try catch opponents off guard, but we all laugh at him for it because he rushes it so much that he usually double faults.