I don't think any gun control "could be effective at cutting crime". Some laws, regulations, requirements could surely prevent someone from doing something, but there is always going to be someone else more determined, and more able to bypass those laws and still get a gun, and if not a gun, then some other weapon that will inflict harm and pain on innocent people.
When those laws start to interfere with my ability to get a gun, one of those innocent bystanders, etc. then not only are they not effective laws, but counter-productive at preventing anything, but rather cause a scenario with more victims unarmed. Prime example is the school gun-free zones. I would be all for a gun-free zone at school, if I thought that the likelihood of it actually being a gun-free zone would occur, and not just a place for a crazy to go off.
One other thing I find that would help lower the rate of violence, gun related and otherwise is a sense of personal accountability for ones self and a higher regard for human life. This is, IMHO, one of the single greatest causes of violence and the need for these school shooters and mall ninjas to kill. Parents are not teaching or instilling in their kids the value of a human life. Lack of parents instilling this, added to the violence seen on tv everyday through cartoons, daily shows, primetime shows, etc. it is no wonder we have the violence we have in society. There are a million other little things that could be done to 'help' the situation, but none of them would ever be a one-stop cure. Take tv's out of kids rooms until they are responsible enough to watch things, know what things are bad, etc. Watch shows together, and take away the babysitter effect of tv.
Overall, no laws would ever work, its the work of the parents that would help curb violence in the long run. That with a better justice system that puts away offenders for a long time, sometimes forever.