These could be used to make pipes and wires, great for detail.
Having L, T and cross pieces would be great too.
How would they be placed? There would be no way to secure them they would alwasy Float
Have them work like regular bricks, you can build on them and place them on other bricks and terrain or interior.
Sure the poles would appear to be floating but in a game with characters that have floating limbs it wouldn't be the most disturbing thing.