Why you want to work with voxels in a mesh based application, and more precize paint them ???
I could point you to various pointcloud tools that convert voxel alike data to 3d meshes.
Or i could point you to scuplting tools inside blender, a much better way of painting apealing 3d meshes.
And if you aterwards like to blockify its (ala minecraft) then there is a remesh modifier who could do that.
Or you might use bump / or replacement maps, they are all a level quality higher then raw voxels.
Can you explain why you like to paint with voxels ?
As it might be that there is a better way to get the end result you want
It’s not really a question of why, just that I want to know how to paint with voxel cubes in blender. If you want an answer to your why, then I guess it is to use cycles materials on voxel art. I don’t want to remesh, I want to create voxel art the same way I can create pixel art.
Blender is not a voxel application. It doesn’t understand what a voxel is and can’t edit them (unless you count the smoke volumes). There is currently nobody working on it.
Try 3d Coat. It’s a bona fide voxel sculpting app.
Blender can make cubes. I’m looking for an easier way other than duplicating and vertex snapping.
Cubes are not voxels, but fair enough. In that case you’re going to have to write yourself an addon that does what you want.
No voxels; but try dupliverts? Anyway; parent a cube to a mesh object for example a sphere. Then on the sphere object properties/ duplication panel click on verts.
You can convert the result to a seperate object with ctrl+shift+a (Make duplicates real (Object/Apply Menu)).
I think this thread would be more appropriate for the technical support section but:
if you just want to have a minecraft kind of voxel looking mesh try to skulp what you want and use the Remesh modifier on “blocks” mode.
If you really want to have cubes in the volume of a mesh you can try the partcile system set to “emit from: volume” and “Grid” in the emission panel. Then set the emission start and end to frame 1. In the physics panel set it to No physics. in the render panel switch to object and select a cube in you scene as “dupli object”.
As I have stated before, I do not want to remesh. I know how to remesh! I want to know if there is a way to manipulate cubes in a similar manner to, say, a 2d level editor where the cubes are snapped onto a fixed grid or something. AND IF BLENDER CAN’T DO IT IS THERE A 3RD PARTY SOFTWARE THAT CAN DO IT AND EXPORT AN OBJ FILE??
Ooh! Thats nice 
Thanks!
I want to kiss you a million billion times. ^^ ^^ ^*^ Thank you my friend