http://www.scientificamerican.com/bl...sc=WR_20100622
and here:
http://arxiv.org/abs/0903.0399
I remember one very interesting experiment from my student days (back in late '60-ies): It was a laser, stimulated by moving EM shock wave front produced by discharge in the focus of the paraboloidal-shaped edge of flat plate made of dielectric material (FR-4 epoxy-fibreglass , used for printed circuit boards).
The shock front was moving at the speed of light along the laser tube.. but it could have been moving faster if the angle of the laser tube was smaller (similar to what was described here in this SA article, if I understood the text correctly)... only in that case the laser effect wouldn't be possible.
EDIT: Laser tube was inclined at 45° in relation to the axis of the paraboloidal shape of the plate.
I don't remember if experiment was a success or not at the end (was this laser working or not..).