As noted by the Bad Astronomer a comet that was until last night 17th magnitude (too faint to see with even many modest amateur scopes without ideal conditions), suddenly got over 400,000 times brighter in a single night and brightened to ~3rd magnitude!!! This is visible to the naked eye even under typical light pollution!
I grabbed my telescope and headed outside tonight to find it. The first thing I found was that my finder scope was misaligned, but once I fixed that, the comet was quite easy to find. Sadly, I didn't have a good camera with me and even if I did, it's quite difficult to get it set up to do the longer exposures to get good shots of comets, but I tried snapping shots through the eyepiece with a point-and-click digital.
One shot came out fairly close to what I actually saw through the eyepiece, so here it is:
Typically, when comets get significantly brighter it's because a large pocket of gas was liberated and spewed off into space. But the halo of this comet seemed amazingly symmetric. I was hoping to see a bit more lopsidedness if there was such an outgassing. Very odd, but very cool all at the same time.