So, wait, are you all calling the kind of beard Santa Claus has a Neck Beard? I googled it, and the pictures I've seen all basically look like a standard beard. You can't grow a beard, with just the hair strictly above the chin, unless you want to look like Wookie or whatever from Star Wars.
http://chubarama.net/wp-content/uploads/2008/04/91894464-1.jpg is a good example of a neck-beard. When keeping a beard, you still have to shave the neck, up until about the part your neck forms into the chin. It's just looks better. Some people have to actually shape their beards right like that, and even shave the upper cheek. Depends on your face.
Edit: Now http://img2.timeinc.net/people/i/2007/stylewatch/blog/070917/george_clooney_300x400.jpg is what I call a well kept beard. Notice how the neck is shaved?