This might be the oddest answer you'll get but... These same proteins that are good for you leather are good for your own skin, too! Rub a small amount of butter around your hands, or other dry/damaged areas of skin. Rinse off with a mild soap and water, and you'll feel the difference. Butter also keeps cuticles soft and flexible, and fingernails less brittle.
Butter is excellent for treating skin irritations like a nasty rash. Rub a generous amount of butter on these irritations twice a day. Allow it to air for an hour or so each day. Cover with a bandage after applying the second daily coating of butter, and within a few days, the wound should be gone.
If you run out of shaving cream, and need smooth skin in a pinch, use a knob of butter on wet skin and get a nice, close shave.
Butter is also an excellent substitute for hair conditioners. It provides essential amino acids to fine, limp hair. Comb a little butter through your hair after you use your regular shampoo. Rinse the butter with moderately warm water for a shiny, healthy head of hair. Take that Pantene Pro-V.