Every once in a while someone will respond to a post with the phrase, “Oh snap!”. For example, the second message in this thread:
http://boards.straightdope.com/sdmb/showthread.php?p=14185272
What does it mean, and what was its origin?
I’m with you. No clue at all. I’m guessing it’s like “pwned” or something; I’ve never heard anyone say it.
“You did NOT just say that!” Usually carries an amused rather than confrontational connotation.
Appears to have originated with Tracy Morgan on SNL.
An article with some possibilities as to the origin: The Mysterious Origins of “Oh Snap!” - Reluctant Habits
My bad: it didn’t originate with Morgan but it was popularized by him.
Usually used after a “diss”, e.g., “Oh snap, he said you a trifilin’ fool”
It’s just a simple exclamation that can be used for a variety of purpose ( “Oh snap, I realize I forgot my keys”).
Suranyi and Candyman74, just curious but if you are Americans, how old are you?
There’s the idea of snap as in “snappy comeback,” indicating wit, style, concision. Some occurrences of “oh snap” are clearly working this connotation, but I think it has been unfortunately diluted or conflated with use as a simple exclamation, where it means no more than “oh wow” or “oh shit.”
I’m not.
Its usage is diagrammed here: Flowchart | Criteria for the Proper Tactical Usage of the Ph… | Flickr
It’s supposed to be a response to a witty or clever insult, IME.
BTW No intention to be snarky. It just always makes me curious what kind of background someone could have to not have heard of/have understanding of, words and phrases that I take for granted everyone will know.
When I was a cashier years ago, I was mystified when a customer asked me some questions about a product, and after answering them I asked her “Would you like to pick it up?” she looked at me with the world’s blankest expression and repeated “pick that up?” I couldn’t be sure if she seriously did now know what the phrase meant or if she was just trying to be incredibly obnoxious so I said “would you like to…purchase the item?” in a cornball voice.
The answer is simple and universal: one that is different from yours. 
…I know, that was the point of asking, people different from me are interesting, people the exact same as me, not so much.
For many people “picking up” a purchased item means getting it at a later time, or going somewhere else to get it. Think of “picking up a pizza” (after a phone order), or warehouse-type stores where you pay one place and then pick up elsewhere. So I can imagine your customer was just confused about how your store worked, thinking “but I’m here now…”
It was a grocery store though, so i can’t imagine what the ambiguity was, since she had brought the item to the checkout stand and was asking me questions to try to help her decide whether to buy it. I do believe the woman was just trying to make fun of the way I talk.
Ok, I totally heard Hannibal Lechter faking a West Virgina drawl there.
To “pick it up” in any context in which an item is sitting right in front of me would, for me, mean only one thing: reaching over and lifting it up in the air. I have never heard that phrase used to mean merely “pay for it.”
It’s a latter-day equivalent or “darn” or “fudge” or “shoot.” That is, it’s a clean expletive that people sometimes use instead of saying one of George Carlin’s “7 words you can’t say on TV.”
This is correct.
Not only did it not originate with him, it wasn’t popularized by him either. All the kids I knew in my brief 2-year stint in New York used to say this, and that was 40 years ago.
We would never have used it this way, but I guess, like most slang, its use may have evolved somewhat.
Actually, it is an approving, somewhat incredulous response to a witty, clever, and unexpected insult.
I have never heard it used this way.