I am from L.A. but now live in an “unnamed midwestern town” and I do notice a difference.
People are more friendly and polite in general, and more “neighborly.” The first winter I was here some strange man was (get this) shoveling the snow off of my front porch! Just to be friendly and neighborly, I guess. My response? I hid in the other room. Hey–I’m from L.A., I’m paranoid and was never used to the concept of “neighborly.”
And people will (get THIS!) let you cut in front of them in traffic!!! This never ceases to amaze. They will STOP and gesture for you to get in line. I will never get used to it. (And yes, I reciprocate and let other drivers get in front of me too–I figure it’s only fair.)
On the other hand, yes, I have noticed more open racism. I can’t say that L.A. (being the home of the L.A. Riots) is clean from racism, but people seem to be more “careful” out there. Out here, people figure that if you are a white (and I am) that they can spout off whatever racist bullshit they want to. It’s happened to me quite a lot, and each time my eyes bug out with amazement. They don’t know that my sister’s husband of many years is black, and that I really don’t appreciate hearing that crap. (But I will tell them my feelings, of course.)
I also notice a certain amount of “What does California have that we don’t have?” (in response to my frequent visits back home), to which I respond, “Oceans, Disneyland, my relatives, Yosemite National Park…” I do notice a certain amount of xenophobia amongst some people here, but I think it depends on the person, really. I don’t think that everyone here feels that way (far from it). To be honest, I know there are a lot of cool people here, and the pottery here is good. (In my opinion, mega points go to a place with good potters and pottery, and this place has some excellent potters, so I do appreciate that.) 
In small town midwest, (Note to you coastal folks… small town means under 2,000 people. Yes, there are places that small and they have miles and miles between them.) People know each other and each other’s families. Locks are rarely needed. People meet and happily socialize all the time. Sure, there are petty rivalries, pointless feuds, and a few bad apples, but all in all pretty friendly.
But… In small town midwest, you mainly only meet the people that you have always known. Where would you get the practice at greeting new people and making them feel welcome? In my neighborhood of 20 houses, we had about 3 houses change hands in the 15 years I lived there. People are good at what they practice. People are comfortable with what they are used to. Take a town filled with Wally and the Beav and then throw in George Castanza, and people will feel a little uncomfortable. They won’t know how to act. There is a goodly amount of racism in small towns for just this reason. Most people in small town midwest have never lived with hyphenated Americans of any type. Change is a scary thing, and tensions build. For the most part it is not racism with evil intent, but I have to assume that it is just as painful anyway. Sooo, the new neighbor doesn’t feel welcome, and doesn’t stay long enough to become a part of the town.
In small city Midwest (20,000 -100,000 people) it all depends on what neighborhood you move into. New subdivisions are designed to minimized contact with neighbors. Drive home, automatic garage door, neighbor gets swallowed up. People move into and out of them with great frequency. The new person has to make a great effort to meet people. Older areas tend to be more established, and with longer term residents comes more desire to meet the neighbors. And areas with actual honest to goodness front porches and sidewalks that actaully go somewhere worth walking? Ahh, those are the best. Meet neighbors left and right. A pox on modern building practices and urban sprawl.
The friendliest people by far are in Australia hands down!
Here in Austin, when I encounter large numbvers of out-of-towners, it’s typically on the day of a U.T. Longhorns football game. And while it’s probably unfair and inaccurate to judge an entire state by its football fans, I have to say… the people of Nebraska are maniacs, but they’re the NICEST and most polite maniacs imaginable.
All of you freakin A-holes are wrong! Unless you are an ingorant jerk, you would know that we Ohioans are the nicest. See.
Grew up in Michigan, then moved to Virginia. In terms of out-and-out friendliness without regard to whether they know you, Southerners beat all.
I moved back to the Midwest for grad school and really noticed the difference.
Damnit, I grew up in Nebraska, not Michigan. Sheesh.
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Wow, SkipMagic, you lived in Parsons–how freaky is that? What’s really strange, though, is that I frequently meet people who used to live there/have relatives there/been through there for one reason or another … odd for a town of 11,000 or so (and shrinking). I might start a thread about that.
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Okay, back on topic (sort of): I may be a bit prejudiced, seriousart, but for friendliness in KC I’ve found that the Northland is your best option. Also, I’ve lived here for more than 10 years and have never been threatened by anything worse than road construction.
I’ve got some semi-relatives who live in Parsons and I’ve been there on more than one occasion.
It never ceases to amaze me that pestering a total stranger with meaningless conversation is considered “friendly”. 
Is there really any objective measure of “friendly” that allows friendliness to be determined in a few minutes with smalltalk?
Personally, I think people are pretty much the same everywhere, except that everyone is different.
To my mind, “Minnesota Nice” is the epitome of “surface friendliness.” People around here have trouble expressing any negative opinion or criticism. An overused crutch phrase that gets used is “well, it’s different” to describe something they don’t really like.
“Minnesota Nice” also seems to entail being too polite to pass someone on the highway. Never before in my life have I seen two cars traveling abrest, one in the left lane and one in the right, going the exact same speed for miles along a stretch of highway. Yet I see it here all the time. Weird.