Speaking of LEDs, Ars has some details on the Bay Bridge's display. Many challenges apart from funding and the large power requirement.
I'm conflicted on this one. There is way too much artificial lighting at night and it this represents a lot of electricity, but it is off-peak and cities are lighting overkill anyway.
As an aside one of the few positive benefits of Sandy was going outside early one morning a few days afterwards when the sky had cleared for the first time in days and being able to see the Milky Way from Central New Jersey. By the next day enough power had been restored that this was impossible.