It used to be the thing that divided kids from their parents was the music they listened to.  Not any more. The changes of mom and dad being into Arcade Fire the Black Keys is just as good as little Suzy listening to the Beatles and Led Zeppelin. A gadget divide?  Maybe.  But I know some moms who know how to use an iPhone better than their kids. And with parents all over Facebook, even that isn't a big gap. But that does bring us closer.  The biggest difference in the generations these days is the notion of privacy and what is and isn't appropriate to share. NY Mag looks at this new generation gap.  If you've got kids, this may scare the crap out of you. She hands me a Bud Lite. Kitty, 26, is a bartender at Kabin in the East Village, and she is frankly adorable, with bright-red hair, a button nose, and pretty features. She knows it, too: Kitty tells me that she used to participate in "ratings communities," like "nonuglies," where people would post photos to be judged by strangers. She has a MySpace page and a Livejournal. And she tells me that the Internet brought her to New York, when a friend she met in a chat room introduced her to his Website, which linked to his friends, one of whom was a photographer. Kitty posed for that photographer in Buffalo, where she grew up, then followed him to New York. "Pretty much just