Aside for the teen related activities that Mark and Lucy have suggested, I think a teen would enjoy visiting some of the sights that New York is best known for like the top of the Empire State Building, Times Square, a walk to the top of the Statue of Liberty and possibly Rockefeller Plaza. Will an NBC Today Show Concert be going on when he is visiting? http://www.msnbc.msn.com/id/3041478/

Central Park on the weekend is great not only for concerts but to walk, throw a frisbee and just observe what 16 year olds in the US are wearing and doing.

Cheers! Beverly Knoxville, TN, USA