Oooh - a couple more:
A true Chicagoan knows that the prevailing winds are from the West, and that it is colder by the lake (except for times in the winter when it is warmer).
A true Chicagoan knows better than to make outdoors plans before Memorial Day - if that early.
A true Chicagoan knows not to expect long stretches of seasonally appropriate weather.
A true Chicagoan calls the major expressways by names, not numbers.
Hey! That’s happened to me and I didn’t even know it! Back in college, and for a year or two afterwards, I used to go on an annual ski trip to Mts Sutton and Tremblant, with a side trip to Montreal – and every year we’d end up at Peel Pub.
More for Houston:
A true Houstonian who is asked where they live will respond by naming a freeway exit.
A true Houstonian knows which freeways are meant when people mention the Southwest Freeway, Northwest Freeway, Katy Freeway, Eastex Freeway, and Beltway.
A true Houstonian measures distance in travel time, not actual miles.
I have always had car insurance though.
A true Seattleite wears the same clothes whether it’s drizzling or not.
A true Yucaipan:
Automatically spells the name of the city after saying it. Or immediately describes it in relation to someplace somebody might have actually heard of.
Knows which way the wind is blowing by the smell of the egg farms.
Knows every place of entertainment or shopping within 50 miles out of sheer necessity.
A true resident of Providence drinks Dunkin’ Donuts coffee wherever they go, even to their job at Starbucks. Some like it iced, some like it hot, but the ones who like it iced will drink it that way even on the coldest day of the year.
[QUOTE=The New and Improved Superman]
For comparison sake, a good friend of mine who’s lived in San Francisco for over a decade has related to me that ‘true San Franciscans’ never, EVER refer to the city as “Frisco” and never call cable cars “trollies.”
[QUOTE]
Allow me to reiterate: NEVER call it “Frisco”.
The only other one I can think of from the Bay Area is if you refer to a numbered freeway as “The <number>”, as in “The 101”, you’re instantly pegged as a native of Southern California. We avoid the “the”, to wit: “Take 101 to 92 to 280 to get downtown”.
Oh, just remembered a couple of others: “the City”=San Francisco, it’s been this way for a long time. And “the Bay Area” never refers to Tampa Bay, Florida.
A true resident of Providence knows that ordering “cawfee reguhluh” gets you hot coffee with cream and sugar, and that this is the real way to drink coffee.
[QUOTE=Airblairxxx]
If they refer to “the 405” and “Ontario” in the same breath, they could also be from the Canadian side of Niagara Falls. 
Except for “North Queen Street” in Etobicoke.
Speaking of which…
A true Torontonian knows:
– that the last two letters in “Etobicoke” are silent.
– that “Vaughan” rhymes with “Strachan”. And that both are one-syllable words.
– that the middle syllable of “Eglinton” is pronounced “ing”.
Yeah, me too.
I never noticed that I did the travel time thing, until I went to college, and I’d say “it’s about 15 minutes away”, and the response was always “Yeah, but how far is it?”.
I don’t understand the one about the water- I grew up drinking the tap water, and am none the worse for wear.
And as for the Austinite one about 19th St. and First St., I didn’t even know they’re MLK and Cesar Chavez; my girlfriend always talks about First & 19th, and I just learned the streets as that. (she’s from Austin originally, and I’ve learned my way around through visiting her family).
Or they order “Milk, no sugar”.
True residents of Providence all know someone who has been to jail, only they call it the ACI.
I went to xxx once, but only for the night. 
The true Torontonian knows that Etobicoke is not part of the City of Toronto. Neither is Scarborough, North York, East York, or any other Metro jurisdiction that isn’t the pre-1997 City.
Hell, the really true Torontonian is still coming to grips with the creation of Metro in the 1950s.
You’re a true Atlantan if:
[ul]
[li]You’re OK with not being able to get a good Chicago-style pizza, as long as you can get good barbecue.[/li][li]You are not at all frustrated by directions that begin “Go down about two miles til you come to that building that used to be…”[/li][li]The words “What’ll ya have, what’ll ya have” cause Pavlovian slobbering.[/li][li]You think ‘grease’ is the cornerstone of the Food Pyramid.[/li][li]You love Jimmy Carter, whether you agree with his politics or not.[/li][li]You know that real cornbread is white, and tastes like bread, not cake. ‘Jiffy’ mix is not cornbread.[/li][li]It’s still just ‘Hartsfield’ to you.[/li][li]You don’t care whether Barry Bonds retires or breaks a leg, as long as it happens before he can break Hank Aaron’s record.[/li][li]You’ve been drinking ‘Cokes’ all your life, but you’ve never had a ‘soda’ or a ‘pop’. [/li][li]You remember when Six Flags Over Georgia was more than just asphalt and rollercoasters.[/li][li]You know that most of the time, I-85 straight through the middle of Downtown will get you to the other side of town faster than the 285 Bypass that was built to avoid all the Downtown traffic.[/li][li]You know that ‘you’ is singular, ‘y’all’ is always plural, and ‘all y’all’ means every last damned one of y’all.[/li][/ul]
OK, so a couple of those were just general Southernisms, but what the hell…
Also, having married a Yankee girl from Vermont (it’s OK, she’s been converted), I am amazed that people from Vermont don’t screw themselves right into the ground with all the ‘turning around’ that they do. “So I turned around and said…, and he turned around and said…then we all turned around and went to the store…” Southern hospitality be damned, I can’t hold a conversation with her visiting relatives for more than five or ten minutes at a time. Drives me batshit.
Is this just a Vermont thing? I’ve never heard anyone else do it.
A true San Franciscan knows that summer is the COLD time of year.
A true San Franciscan knows to dress in several layers, because no matter what the weather starts like, it will change about 3 times depending where you go.
A true San Franciscan wouldn’t be caught dead at Fisherman’s Wharf.
A true St. Louisian knows that “Where did you go to high school?” is a polite way of saying “Tell me everything about your socio-economic status.”
A true St. Louisan refers to streets by the names they had 30 years ago, not by what the map calls them.
A true St. Louisan knows real pizza has thin crust.
A true St. Louisan knows the best barbecue comes from places that used to be gas stations.
A true St. Louisan really does pronounce it “Highway Fahrty.” But never “Missourah.”
A true St. Louisan knows the only real “Historic Route 66” is the Gravois-Chippewa-Watson alignment.
A true St. Louisan drinks Busch, not Bud.
Ha, you beat me to it. I was going to post “A true Buffalonian has never ordered ‘Buffalo’ wings.”
Other thoughts:
True Buffalonians will engage in a 45 minute debate on where to get the best kimmelweck.
True Buffalonians enjoy a good Butter Lamb, whether or not they are celebrating Easter.
True Buffalonians eat “fish fry,” never “fish and chips.”
True Buffalonians probably need to keep an eye on their cholesterol.
True Buffalonians can tell you where they were on January 3, 1993.
True South Buffalonians still haven’t figured out what was wrong with the advice to “grab a six pack and stay home” (given by the Mayor on the occasion of the Blizzard of '77) Maybe he should have said a case?
True Buffalonians will panic and pray to the Infant of Prague if they are visiting friends in, say, South Carolina, and there is a freak snowstorm and the born-and-raised South Carolina friend is behind the wheel and won’t pull over to let the only True Buffalonian in the car drive. Okay, maybe that is just me.
Austinite here, though I was not born there… my wife was though. 78744 in the house baby!
Maybe it’s a South Side/East Side thing, but MLK has always been MLK… if you call it 19th Street I’m gonna question your politics. Chavez is more recent so I might let it slide.
A true Austinite is from North, South, East, or West Austin and resents Austinites from other parts of town. Especially us South Austinites. John Kelso is an exaggeration but he has it basically right.
A true Austinite has a favorite Hut’s burger.
A true Austinite can trace the movement of the anchors on the news stations, and remembers when channel 36’s call letters were KTVV, and listened to K-98 on the radio.
I’m sure I’ll come up with others…