Mini Helicon Plasma Thruster
Researchers at MIT have produced an advanced miniature plasma thruster, using the same principles as the VASIMR (Variable Specific Impulse Magnetoplasma Rocket) plasma rocket that NASA has been developing for deep-space applications a number of years now. The mini helicon notably uses nitrogen, instead of hydrogen that VASIMR uses, and the neon and xenon of other ionic thrusters currently in use.
The most interesting part of this research is that students built a thruster out of an old glass coke bottle and an aluminum can, to prove just how simple and hardy the system is. A short video is in the link above, complete with the characteristic sky-blu glow of the nitrogen exhaust.