It would seem that for a couple of major west coast cities (Seattle, San Francisco), things weren’t so Comcastic, as hardware failure caused Comcast’s DNS services to fail. This overloaded the remaining DNS servers, causing DNS resolution failure.
This means that any DNS lookups failed or just timed out, and that nobody could get to websites or other services. The easiest way around this is to switch to another DNS service like Google (184.108.40.206 and 220.127.116.11) or OpenDNS (18.104.22.168 and 22.214.171.124) and ditch Comcast’s DNS completely. Or, you could go one step further and run your own local DNS. This is what I’ve done.
Setup is super easy: Install Linux on a spare computer, and then install Bind, and configure it as a caching DNS server. Now, point all your computers (or just your router, if it will let you specify DNS servers manually) at your local DNS server. If you’ve never installed Linux before, it’s a great first project. The result is lightning fast DNS lookups, since your computer is doing the lookups on a computer that’s no more than 1ms away, instead of 10-30ms away if you’re on cable, or 80ms away (or more!) on DSL. On my crummy DSL it made a pretty good difference.
Now that you’ve got a Linux box on your network, you can do fun stuff like set up Plex, a Minecraft server, or whatever you want to fool with. It’s quite handy!