There is a lot of good advice on this board on how to deal with SPOT – if you search you get 20 pages of SPOT mentions.

I want to suggest that we collect here the best responses, comments and ripostes to avoid having to get into the SPOT dialogue with the risk of having your trip delayed.

Let me make clear: I am not interested in more “SPOT is unconstitutional!” tirades. Nor “I’d just tell him to stick it and that I’ll report him for harassment.” Nor do I want to read once again that “If you have nothing to hide, you have nothing to fear.”

No, I would like replies that work, or have worked in the past. They should be one sentence, and indicate clearly that you do not want to talk.

The dialogue starts like this:

SPOT: “Where are you flying today?”

Flyertalker: “Do I know you?”

SPOT: “Just like to ask you a couple of questions.”

Flyertalker: <Your ingenious reply here>

One of the better ones I have seen on this board is “Sorry, I’m straight.” (You can use this even if you’re gay ).

You take it from there.

Comrade SPOT: "How are you today?"

Citizen Spiff:

Comrade SPOT: "Where are you headed to today?"

Citizen Spiff:

Comrade SPOT: "Pretty quiet, huh?"

Citizen Spiff:

Good. Eloquent. And to the point.

If you turn around and walk away, will there be any consequences?

None. If they want to waste my time and a law enforcement officer's time, they can, but sooner or later, the police get tired of morons summoning them.

Always answer a question with a question. It's extremely annoying and perfectly valid:

SPOT: "How are you today?"

You: "Why do you want to know?"

SPOT: "Where are you headed to today?"

You: "Do you ask everyone that question?"

Might want to wait until the Swine Flu "crisis" is over for this one :

SPOT: "How are you today?"

Me: *Hacking cough, hand on mouth*

SPOT: "Where are you headed to today?"

Me: *Hacking cough, uncovered mouth 'cause I'm digging frantically in pocket.*

Bonus round:
SPOT: "Do you mind answering a few questions?"

Me: *Pulls blood-stained hankerchief from pocket, continues coughing*

Seriously, mess with me after SYD-LAX and I don't have to fake the first round.

spot: where are you flying today (or how are you today or excuse me, may i ask you a question or <other spot intro here>)

me: please spot someone else, thank you

Bandung* Boy: Where are you going today?

Pax: Where the plane I get on takes me.

SPOT: Where might that be?

Pax: That is completely out of my hands and up to the Airplane’s Navigator--he's over there in the Crew lane--so why don’t you go ask him?

*How appropriate.
So, I'm now required to memorize the 3 letter codes for all 9495 airports around the world? says the TSO. . .

How about "the repeater"?

SPOT: How are you today?

Me: How are you today?

SPOT: Where are you flying to today?

Me: Where are you flying to today?

To top it off, put a little more emphasis on "you" when asking them.

Spot: How are you today?

Me: Fine, fine. Hey have you ever thought about a pre-need funeral policy? In today's uncertain economic times when prices are going up....

Me: Hey where are you going?

Me: Hello?

You can do the same with religion, Star Trek, Star Wars or any subject that people find annoying.

Then hand him an ASL card.

Would recognizing that you know they are a behavior detection officer be amusing? Are they supposed to be incognito? Seems like they are "secretly" trying to detect your behavior, at which point blatantly telling them you know EXACTLY what they are trying to do kind of defeats the purpose of them asking you questions.

No, I'm won't communicate with them in any way, ASL included (and I don't know much ASL).

I figured there would be one certain type of sign language you might use with them...

Ciao,
FH

Certainly one gesture, but not at the checkpoint. That would still be a form of communication.