Certain lineages of Hung Fut have a one armed form. Hak Fu Mun (Black Tiger) also has a one armed form. In Black Tiger once you learn this form and it's applacations, you can only fight/spar in class with one arm. You must use your weak arm, this form helps to even out your fighting ability with both arms.
Here's a video clip of one of Hung Fut's one armed forms.
http://www.youtube.com/watch?v=VuJ7X89gdlM
jeff
