As part of the promotion for his new movie Marjorie Prime, actor Jon Hamm has teamed up with Holo, an app that lets you view and make videos with holograms of famous people.
It's weird, but really, really cool.
Jon's character from the movie called is called Walter Prime and he's actually a hologram in it so it works out for everyone, including us who now how a "pocket Hamm" to take with us wherever we go!
Confused? It's ok, the video below will explain everything.