I do have one, and I usually carry concealed. I hang out on this site because 1) I support the right to bear however you choose, open or concealed, just as the 2A specifies, and 2) I seem to find more people on this forum that support ALL of the Bill of Rights than on most other gun forums; so, even though I don't often carry openly, there is still plenty in common with lots of folks here.
I have a permit because Arizona requires one to carry concealed, and I don't want to be charged with a crime if I have to defend myself. I don't LIKE that I have to have a permit, and I feel it is unconstitutional, and hope for and work toward removing that requirement, but since it is there now, I got a permit.
One thing I do like about it is that when I buy a gun, there is no NICS check. So, while there is a record of the purchase (4473), the government won't know about it unless they do a search of records of that particular store. Of course, I also believe that the 4473 and the background check are unconstitutional as well, but you can't buy a gun from a FFL (another thing that is unconstitutional) without them.