ooohh, a good question Mike... you can always hide the object via selecting said object and then going up to Display>hide selection... but I do not believe that there is the same type of simple to use object lock as is found in say Wings3D... least ways I have not found such to be...

there is always the option to create said object, save as... then delete said object from the scene and then load object back into said scene as an instance, which though scalable etc said object is not editable unless deinstance instance command has been selected... sounds confusing? it is.. to me anyways... better to go the hide selection route hmmmm very good question indeed, thanx for asking that... here's hoping Ivan can shed some new light to this that we have perhaps missed for whatever reason