I don't get it

Accents, slang, and sayings are all colloquial to cities, towns, and states. Yinz, y'all, yous; they all mean the same thing. Even though people in California probably never say "yinz 'n 'at", when used in a sentence, Californians could figure out the meaning. Maybe. Although, they might be to busy surfing and dying their hair blonde, right Peter and Phong?

At any rate, one such colloquialism (and relatively new-found, I believe) that I just do not understand is the use of "on line". Here in New York, when one is standing in a queue, it's common to refer to waiting as "being on line." This makes absolutely no sense whatsoever. None. None at all. What's worse- people I know (NOT native New Yorkers), use this exact phrase! It's not correct, people...not even a little bit. Honestly, how can one be standing ON line. Unless there is an actual line drawn on the street, and waiting involves physically standing on said line, it's wrong.

I won tickets to the Daily Show (!!), and I received my confirmation email last night. Under the "Terms and Conditions", it says, "Your guests may meet you on line until 4:30pm. Past 4:31pm they will not be allowed to meet you on line."
!!!!!!!!!?????????????!!!!!!!!!!!
TWO uses of "on line" in ONE sentence????? In a published document? Dear God.

From now on, whenever anyone says "I can help the next on line", my response is going to be "thanks 'n 'at up unnereef 'er...goin dahntahn 'n see yinz later 'n 'at." Then they can look at me funny too.