Behodar:

 

Same here, never been asked for ID on a domestic flight. When you think about it, why should you be? You don't need one on a bus or train, so why should you need one on a plane?

 

I didn't travel by air much prior to the 9/11 attacks, but I was under the impression the current ID rules date from the response to the 9/11 attacks? Old news now but that may have been the reason for ID checks being fairly common in those days but having become more lax these days. Or did the rules exist prior to 9/11?