As I was returning home this evening, I got off the bus and saw that everyone was gazing up into the sky. This is what they were looking at. (Click to see it in the Gallery.)
I don’t know how it got there, nor exactly how big it was… it looks to be a couple of seven or eight hundred feet up. It dissipated over a period of about a minute from when I took this.
Odd, innit?
UPDATE: I guess it was due to fireworks. (But who lets off fireworks in daylight hours on a cloudy day?) Check the comments for a link to video evidence.