The president should ban currently legal accessories that turn semi-automatic weapons into de facto automatic weapons.
Manufacturers are taking advantage of loopholes in existing laws to sell these items.
For example, there is an accessory called the "Slidefire" sliding stock that can be easily attached to a variety of firearms, including the AR15 (the weapon recently used to kill 20 children in Newtown, CT) to "bump fire" and accurately fire hundreds of rounds a minute.
http://www.youtube.com/watch?v=cm7GkBT1Gew
Attached to a semiautomatic shotgun:
http://www.youtube.com/watch?v=j_W1pLT7
(If these videos are removed, there are literally HUNDREDS of others out there, so you will not lack for supporting evidence. Search for "bump fire" or "slidefire" or "sliding stock".)