Unique way of using a doppelganger?

Say you had an identical twin, who nobody knew about. What would be a unique way of using his similar appearance, granted that he agreed to do what you were asking?Unique way of using a doppelganger?
You could commit a murder in front of a TV camera, and each could accuse the other of the dastardly deed, whilst submitting exactly the same alibi. Of course you would have to be very careful not to leave any personal forensic evidence. With both of you being on trial for the same crime, unless one of you let it slip that you were acting in collusion, both of you would have to be found not guilty due to reasonable doubt, even though it is clear to everyone that one of you is a murderer and the other is not so innocent; I think!
well, maybe not a unique way to ~use~ your twin, but say someone you didn't like asked you out. just pass them on to your twin and let them deal with it lolUnique way of using a doppelganger?
Perhaps a Personal Secretary? Or I think I would use him as a sort of study guide. I research one subject while he researches another,then imparts his knowledge onto me.Unique way of using a doppelganger?
"share" a job or two jobs with them

switch places of work after they get bored with what they are doing
Probably use him in magic tricks as per a certain book/movie.
Have him take a good old fashioned ***-whipping for you
Go to school for me.