removing old plaster from walls

We are attempting an inexpensive remodle of our bathroom. The house was build in the 50's and has old textured plaster walls. Some of the plaster has cracked and chips away easily. Other parts will not come off. Is there a product that you can get to help remove the plaster and then ready the walls to be painted without having to put up new drywall. The bath is small to begin with and our concern is that new drywall would make it even smaller. Any ideas?

katcost