White Collar, Season 1

[Neal forges Peter's signature perfectly]

Peter:
How did you do that?

Neal:
Well, your hand is programmed over years to write letters a certain way. Try to mimic someone else's, and your style will always creep in. But, turn the signature upside down and it becomes nothing more than a drawing, all you have to do is copy the lines. The preconceptions about letters go away and you have a perfect signature.

Peter:
That's a neat trick. Don't ever copy mine again.

Neal:
Never again.

Peter:
You have copied my signature.

Neal:
Let's... focus on the crime at hand.