Xtra Normal provide quite a useful tool for quickly scripting a cut-scene or conversation in a game. There are quite a few character to choose from and you can insert pre-set camera angles, animations, expressions, looks, pauses & sounds. these can be inserted at any point in the conversation so the degree of control is fairly good considering the point and click nature of the interface.
This would be a really quick and useful tool for a mock-up of an in-game conversation or to convey camera angles and dramatic pauses. Even the free movies can be published straight to YouTube. The tool is worth a look. The video below is just a couple of minutes worth of work.