Nick Lachey was the host of Teen People’s “20 Teens Who Will Change the World” event yesterday in New York. Teens honored included young “Lost” actor Malcolm David Kelly who is a youth mentor, Cody DeWitt, a 19 year-old filmmaker who documented his mother’s battle with cancer, and Shannon Sullivan, a 14 year-old champion for Internet safety.

Lachey made a surprising move last month when he announced that he was concerned about teen safety online and was starting up a teens-only social networking community to compete with MySpace. Lachey may have just been lending his celebrity to help some of his childhood friends, who developed the site. It is called Yfly and is now online

Lachey is featured on the cover of the this month’s Teen People, which includes an article about selfless teens. Here is Lachey at the event. The woman pictured with him is singer Natasha Bedingfield, who performed her songs “These Words” and “Unwritten.”