Gamma Ray Bursts are colossal cosmic explosions: in their death throes, supermassive stars collapsing into a black hole will send out a pair of powerful rays from their poles that carry away most of the energy of this incredibly violent event in a second-long burst of intense radiation, radiating away more energy in the blink of an eye than the Sun will during its entire lifetime of billions of years.
Fortunately for us, these ultraviolent events are incredibly rare and thus most of them happen billions of lightyears away in distant galaxies -- a gamma ray burst in our own galaxy could well mean the end of life on Earth if it was directed our way.
Yesterday, the gamma ray burst GRB 080319B was observed. What is so special about this one is that it has been determined to have happened at a distance of 7.5 billion light years, and yet its optical afterglow was briefly visible with the naked eye!
If you had been looking up at the sky in the right direction at the right moment (and outside a big city), you could have seen a brief blip in the sky, thus witnessing the sight of an incredibly violent cosmic event that for a brief moment outshone an entire galaxy by a factor of a million or so. To put things in perspective: had this burst happened in a galaxy a little closer to home, the Andromeda galaxy say, it would have been by far the brightest object in the night sky.
Reports of observations are coming in right now, and in the rather unlikely event that you happened to actually look up and take a photo of the right piece of sky at the right moment, I'm sure the astronomy community would be thrilled to have a look at your pictures.