A colleague brought this article to my attention. Slightly off-topic,
but interesting nonetheless:
"Researchers at UC Berkeley, along with scientists from
the University of Oregon and the University of Illinois,
say they can slow the speed of light in a way that could
help speed the delivery of movies to your PC.
"Scientists at the university managed to slow the speed
of light traveling through a semiconductor to 6 miles a
second, or 31,000 times slower than the 186,000 miles per
second that light normally travels in a vacuum.
"Slowing the light pulses could lead to a more orderly
traffic flow in networks, ....."