In real life, most teens and tweens can't hit the clubs or crash late-night parties. (We're ignoring Miley Cyrus.) But on Funji, the first avatar-based social networking app for the iPhone, "they express themselves to friends in a virtual world, whenever and wherever they want," says creator Shinyoung Park, who was a winner of Facebook's fbFund competition last year. In Funji, teens get "points" for having conversations with other avatars, which they can redeem for virtual goods, such as new backgrounds and accessories. And soon, they'll be able to tease friends by shaking the iPhone or kiss others' avatars by kissing the smartphone screen. Since its October 2009 launch, Funji has lured 20,000 users--a far cry from bigger virtual worlds like SecondLife--but teens spend an average of 10 minutes at a time with Funji, compared with just one or two for most apps. And Park, who's now developing similar apps full-time for interactive-games publisher PlayFirst, is optimistic about the technology's future. "We're going to be seeing a lot more avatar-based apps, especially on smartphones," she says. "They're the best way to attract young people."