I'd think that I would be very recognizable in most environments, but an "A" made out of my two index fingers and left thumb, with the thumb at 45 degrees, would suffice for a standard signal. It even looks like the Aetherlight logo.
You just have to be careful not to turn it into a triangle - that's the Amaranthe signal. Very different company, that is.
What, you're going to take away my fun of me walking up to suspected Aetherlighters IRL, introducing myself normally, and seeing if we can find the same common ground that has been previously established online for years while smiling like a shameless troll?