Coalsmoke,
I agree: Taking the regulators off and locking them in the toolbox for the evening is the best solution. My situation is probably a little different than most, since I'm a moonlighting welder. Some nights I'll get 2 separate calls for short 30-minute jobs: One at 5:30 PM, and the next at 9 PM. After a while, the lazy factor kicked in, and now the regulators stay on the bottles.
Will the connectors ever wear out from all that "on and off" action? I crank down pretty good when putting my regulators on, and my brass "regulator nuts" (LOL - that sounds funny) look like they might eventually wear out.