Overheard In New York, a few choice selections:

[on the 6 train]
Man in Jews for Jesus t-shirt sits while well-dressed young man across from him unbuttons shirt, takes out black marker, and writes 'Buddhist 4 Mohammed' on his undershirt, standing and aggressively staring down Jew for Jesus.
Buddhist guy: Give me zee money, Lebowski! I fucks you up! We want zee money, Lebowski! Give us zee money or we fucks you up! [Steps to the left, and in a different German accent] Ya, give us zee money, Lebowski. My girlfriend cut off her toe 'cause she thought we would get zee money. Iss not fair.
Jew for Jesus: [Silent, calm.]
Buddhist guy calmly sits back down and buttons his shirt, turning to small Hispanic boy next to him: And that's where babies come from.

[G train Hoyt/Schermerhorn station]
Blond Tourist Bimbo: I've never even heard of the G Train.
Blond Local Bimbo: Yeah, it's a ghetto train.
Blond Tourist Bimbo: Where does it go?
Blond Local Bimbo: Nowhere.
Black eight-year-old boy: Except my home, bitch.

[F train]
The subway doors open. A hobo enters, holding a bottle of windex in one hand and a tube of toothpaste in the other.
Hobo: Which is the better time to read Dostyevsky? Winter?
He sprays the windex.
Hobo: Or Spring?
He squeezes toothpaste out of the tube.
Japanese girl: Spring!
Hobo: You are correct.

[Crema Restaurante, 17th & 6th]
Mother with little girl: Excuse me. My daughter wants to know if you're a pirate.
Woman wearing bandana: No. I'm just a lesbian.

[Union Square]
Mother: Don't you ever do that again! [slaps child hard]
Child, calmly: Well, are you happy with yourself?

[Midtown office]
Coworker #1: So what've you been up to?
Coworker #2: The usual. Just whacked off.
Coworker #1: Dude, you're on speakerphone.

and I think this one might be Mark...
[East Village]
Girl: Why are you wearing cowboy boots?
Guy walking other way: I just got off work.
Girl, to friend: Did that guy just call me a whore?