For what it's worth (in bandwidth credits), Chuck Shepard's News of the Weird successfully returns HTTP code 304, and my daemon honors it. So we've got bandwidth green credits to sell.
But yesterday, my daemon got its first URLError -2 (Name or service not known). Geek that I am, it gave me a little thrill to see how the exception was handled, and to add a little code that'll further isolate the exception. Whee! I program all day at the office, then go home and have fun programming a little more. I'm easy to please.