Thanks!

Not *all* the people. : )

On a long ride I usually find at least one car or bike will always flash a
warning. It's the mobile radar that worries me the most. No warning, they
see you speeding, they got you. Usually by the time you work out that that
oncoming car is a cop car too...

Doug Cox.
Work to ride, Ride to work...

 

Index finger pointing straight up above helmet making small circular
movements ala beacons...

Tap right shoulder with left hand signifying epaulettes...

Doug Cox.
Work to ride, Ride to work...

 

Yeah, that one I've seen (and done), normally not quite
above helmet though, more off to one side.

Ummm. I'd be thinking "damn, a bird shat on me!"

The other one is left hand off to the side pushing down,
but I'd normally use that to warn the people behind me
that I'm slowing down for a reason.

-----sharks

 

Turn around and put your face on the pillion seat. Then arch your back so
your legs point straight up in the air, then do V for victory signs with
both legs. No one ever misses this signal.

 

Nor the spectacular aftermath.

G