the cab rides on the airbags. Also, sone of the suspension in the trailers and he rear of the rigs also have. depends on the truck.
They do use air for the brakes, but its not like bags used in your truck.
Not sure if they were first (like before airbags in slammed rides) but some older Lincolns use Airbags. As a matter of a fact, you have to turn them off when you lift them or the bags inflate while in the air and wont deflate when you drop them and then BOOM a bag blows. A guy I worked with in Atlanta leanred the hard way in a tire shop i worked in.