Be someone else in a dream?

Has anyone ever, or does anyone think it is possible to, be someone else in a dream? I can just imagine the possibilities of being someone I hate and embarrassing them. It could also be used to see yourself as a DC and test yourself and your personality.
So...
is it possible? Im going to try it.

I've done this many times; it's certainly possible. It helps to visualize yourself beforehand and really know how you're going to act and what you're going to do.