In Texas we wave! Our state moto is "Friendship," and Texas highways cover more miles than any other state. What else you got to do than wave on long flat Texas roads. Hell, sometimes I wave at cars when I'm on my bike.

I've always believed the "motorcycle wave" is two fingers pointing down for "keep it on TWO wheels" and as a show of solidarity in the motorcycle community. May have started during the surge of WWII soldiers returning with motorcycles after the war, which was a tight group already.