Walls and Ceilings - Can I do knock-down texture myself?

We hung new drywall in our kids' playroom. We've gotten some prices to have a professional
finish it and do the knock-down wall texture, but they are very expensive. It's only a 10x10 room.

Does anyone know of an easy way for us to do it ourselves? Is there a product out there that
will give that look?

Any suggestions/guidance greatly appreciated!

There are a couple different variations you can do yourself. One is called Stomp knockdown. You will need a stomp brush also called a crows foot. It is available at your local home store. It is a brush will long bristles mounted on a wood frame. Also it would be a good idea to get some sort of pan to work out of. In the concrete section they sell a good size pan for about 5 bucks. Get some lightweight mud. Mix it up so it has a consistancy of mayonaise. Load your brush up with mud and simply stomp on the wall or ceiling. Let set up a little, about 10 minutes. This time will vary on humidity, temp, and the look your after. Then knock this down with a 12" taping knife. You can also use any kind of stipleing tool or brush.

Although I haven't personnally used this mud dobber I read about it on another wall thread.

http://www.mud-dobber.com/