As Kristaschafer said above, it is not airborne. It is contact only, unless nasal passages or the respiratory system is involved, and that is EXTREMELY rare and most patients by then are already hospitalized. I'll try to explain it simply.
Consider airborne for a moment, that is when someone sneezes, coughs, breathes on you, so the infection is in your respiratory system. Now, MRSA is a staph infection of the skin, tissues, etc, so it can't "fly" off your skin into someone's nose, or mouth. You must come in contact with it (touch) to become infected.
MRSA is usually spread through physical contact--not through the air. It is usually spread in hospitals on people's hands. Healthcare workers hands may become contaminated by contact with patients, or surfaces in the workplace, and medical devices that are contaminated with body fluids containing MRSA.