That is a called a stipple ceiling finish if you need to know. That is a easy finish to do but it gets very messy. Basically all you are doin is taking a round stipple brush that looks like this http://www.fauxshop.com/images/Stipple.jpg and dipping it into the spackle and hitting the ceiling with it. Not a very hard process, just gotta make sure they are all in lin with each other to make a nice looking finish. I have done it a bunch of times, like I said it is a very messy process though.