In the spirit of Eric Drexler's Engines of Creation, in which the author predicts technological developments based on a visionary's ideas of "what" but not an engineer's knowledge of "how", I present my thoughts on gun control.
We already have PDAs and phones with wireless net access, that allow you to surf and buy and track and find, so I'm suggesting wireless handguns as the next step forward in personal and public safety.
Here's the deal: handguns that only operate for a particular user are already available, made possible by RFID (Radio Frequency Identification Device). This equips a gun with radio waves and an antenna to receive those waves. The waves are transmitted from a ring or wristband worn by the shooter. The gun would be capable of accepting several memory codes; this would be helpful for families that have more than one authorized user. It would also satisfy law enforcement's need to have several officers capable of firing the same weapon (so that, for example, if one officer is killed in a firefight, another officer can use his gun). [Source]
This could be made a mandatory component of all handguns, with one addition: an uplink that logs each use of every gun to a database, which can be searched and cross-referenced by law enforcement. Any firing would be recorded, and the possible users of that gun would already be registered. Normally this sort of data wouldn't be accessed - hunting and training ranges and similar legal and regulated activities have little need of such constant observation. But bullets from the guns would be "tagged" in some fashion as they are fired from the gun, and could be traced to the gun records on-line. Get the bullet, trace the user, put the criminal in jail.
Another thought is a DNA sniffer on the trigger of such guns which would identify the user and then encode or tag that information on the bullet - guns don't need to be registered or on-line for this to work, since alll bullets would be traceable to the person who fired them.
Until the public starts demanding such new technologies to better protect themselves, unregulated purchase and use of handguns will continue to result in needless deaths. This isn't to say that such technologies will eliminate crime immediately, but improved tracking and prosecution of criminals based on these or similar methods will deter such crimes.