What's wrong with leaving the slide back for extended periods of time?
As far as locks go, my gun stays loaded, with one in the pipe, decocked, and cliped to the side of my bed, in an Uncle Mike's Sidekick holster, but, then again, the only "kid" around my appartment is my 18 year old kid brother, and he's a better shooter that understands saftey as well as I do.