Duplicate objects randomly in a delimited zone Is there a tool (a module or a easy method) to duplicate an object many times, randomly in delimited zone (the inside of a sphere for example) ?

Rather like the airbrush tool in a raster graphic editor (illustrated below), but instead of drawing dots, it would duplicate a preselected object : 





Note : I don't wish to use particles systems to duplicate objects (I need to keep control on positions)
See this question for details on how to setup a particle system for distributing objects inside a shape. 

Once you've done that, you can convert a particle system to real objects with &#9096; Ctrl&#8679; ShiftA or the convert button in the modifiers panel:



Note that this won't remove the particle system, so remember to delete it if you are done with it.