One of the ways celebrities are different from you and me is that they might spend their 21st birthday party with their model girlfriend on a 140-foot yacht. And DJ Hero would be the sponsor.
Actor Brandon Mychal Smith is the celebrity we're discussing, an actor I confess I had to Google in order to learn he starred in a Disney Channel movie called StarStruck.
He celebrated his 21st birthday on the Endless Dreams Yacht, which you can ogle at the yacht's official page.
Here's one look at it...
You may note there is no sign of DJ Hero in the above photo, just Smith with girlfriend Jasmine Tookes and some sort of birthday cake. Well, look here and you'll see the playing of DJ Hero, the standing in front of DJ Hero and all sorts of other Hero-related activities perpetrated by the lovely young people attending this party.
Not the party I would have wanted for my 21st, but if you're going for a video game theme (and you're rich and attractive to the Activision DJ Hero marketing team), why not?