There was this infomercial once... Imagine a plastic mask that had electrodes all over it. The premise is that by wearing this device, you would recieve a small ammount of current into your facial muscles. This in turn would "shape up" the muscles, giving you a face lift sans surgery. Fascinating to see such ridiculous devices being pushed to the public.
Others have proposed liposuction. That isn't neccesrily the whole story. Yes, liposuction will reduce the adipose tissue, but the hanging skin will still be there, only now it will sway even more freely. This phenomenon is seen in older people who lose large amounts of weight. Their skin is not very elastic so it just hangs. Skin would need to be cut and the jaw line recreated. It's not a big deal, though, from a scarring standpoint.
There is another procedure that is emerging as a possibility. A device can proect a focused beam of energy that actually destroys fat cells but does not harm the surrounding tissues nor affect the vascular system. I can't remember if this was infra-red or what. I was the IT director at a splastic surgery center, so my medical knowledge of the specifics is cursory at best. Results were not immediate, of course. The body still had to deal with the now dead fat cells. It was not touted as a solution for really fat people, but rather a non-invasive method of body sculpting certain areas.