1. In a computer system that supports a visual user interface designer and a serialization engine capable of saving state for user interface objects created within the visual user interface designer, a method of automatically generating and tracking undo information for changes made to a user interface object within the visual user interface designer so that a developer of the user interface object need not be responsible for generating and tracking the undo information, the method comprising acts of: receiving one or more change notifications generated in response to one or more changes to the user interface object within the visual user interface designer; calling the serialization engine to serialize at least a portion of the user interface object into a serialized format that is suitable for representing the one or more changes; creating an undo unit from the serialized format of the one or more changes to the user interface object; and adding the undo unit to an undo stack.