Cracking joints - good or bad?

I'm coming along with the fundamentals course and doing okay as I'm in pretty good shape and have been really focused on nutrition for the last 6 months. My question is this: I have a considerable habit of cracking my knuckles and back. Occasionally my wrist and neck. You know what I'm talking about. I can and will do this several times a day. There is no pain or discomfort, but I'm wondering if there are any negative implications here. Perhaps I will do it less and less as I become more focused on flexibility and joint mobility? I don't know, but I'm wondering if this is a good or bad thing. Or neither.