5DMKII + 16-35mm F/2.8, 1/5 at f/4.5, ISO 6400.
I was just about to fall asleep last night when BAM! Fleet Week Fireworks outside my window!
I grabbed my camera (which I always keep within an arms length at all times :P) and ran to the window. I tried to take a photo, but no card... arg! so i ran around my apartment looking for a card. Finally found one, but it was full... ahh... formatted the card quickly, took a shot, realized i needed a tripod, couldn't find one... arg... perched the camera on the window sill and snapped about 10 shots before the fireworks ended. Phew!
I shot this at 6400 ISO because of my lack of a tripod or time to really consider what setting would be best. This shot was a bit noisy so I used Lightroom 3's awesome noise reduction to smooth out the graininess.