I think SGTAR15 has hit the nail on the head. More important than locking guns up is teaching childeren proper safetly, handling, use, and potential of firearms. If you destroy the "mystery" about them, they just become another one of dads tools. When I was growing up, my best friends dad had over 20 guns in an unlocked wooden/glass case. We never touched them, because we knew proper safety, and most importantly, that if we did touch them without his dad around we were dead meat.
It is amazing how far a little education and discipline will go. Locking things away is one more step toward safety, but should not be relyed upon as the first line of defense. Kids can find keys, and punch codes until they find the one that works, then all that is left is education and discipline.