For anyone not too skilled and wishing to learn a few quick and easy moves, watch HEAT (Rob deniro) outside a cafe where he despatches a guy with a body blow and face grab.
Also COLLATERAL (Tom Cruise) watch the scene in the disco where he takes out the bad guys.
These moves were all taught by a guy from British Special Forces and they work because they are short and fierce and easy to apply with minimum training by anyone and can be studied on dvd.
On another note face grabs where the eyes are covered are totally debillitating as the recipient cannot see and is under your control with minimum harm to him always grab the back of the head either by hair or just
skull gripped to gain purchase to the face grab and pull on the back of the head whilst pushing the face......
I practice the face grab after using pete consterdines impact punch to solar plexus and have used it a few times in real life.