If you run the game in windowed mode and right click on the window bar (causing windows to freeze the process) you can lock your character doing an animation until you exit the context menu.
You can not really see the effects of what your doing, but to others if you were to take your car off a jump and do this it would cause the car to stay stuck in mid-flight. You can however still take damage, and de-cloak. (Yet you will not regen health or EGO powers as they are clientside)