Plasma aerodynamics offers tantalizing promises of improving aircraft performance. By producing a thin layer of charged particles around an aircraft you can change the behavior of the boundary layer, significantly reducing friction. The charged layer also absorbs radar, improving stealth.
As noted here and here, it is already been in use for decades by the US and Russian military. The civilian airplane makers and the US tax payer that developed it are not using it. There are fuel savings of 10-30%, which would also lower the cost of airplane tickets.