There are a couple of old sayings, "an unarmed citizen is a peasant" and "if you outlaw guns, only outlaws will have guns." Why stop at guns? Baseball bats, kitchen knives, bows, halibut spears, gaff hooks, hell even stickes and stones are all weapons. Run at a cop with one and see what happens. I think they should be banned too, if my gun is. As for registration, we already do it by having a concealed carry permit. Oh, even if you could ban all guns or even registar them all, you can find directions on the net to build them. So we better ban the net too. For those interested the links below are the crime rate in Australia. It went through the roof when they banned guns.
http://www.ocs.sa.gov.au/OCS_Publications_Information_Bulletins.html
http://www.ocs.sa.gov.au/OCS_Requested.html