In the aftermath of Hurricane Irene, I was trying to get information from my local electric cooperative about outages. There were many (including my neighborhood) and I wanted to see the scale of the problem. It turns out, they have a page with a map that shows current outages by zip code.
It’s pretty old-school as far as web maps go but it gets the job done. Their day job is making electricity, not web maps, so I won’t critique it too much. One thing I did notice is that the map seems to be dynamically generated (as do the tables on the page) from some inaccessible data source. I search and tried to find some kind of feed, to no avail.