At about the time I couldn't access Wikipedia from the hotel I'm in at the moment, Wikipedia announces they had a major outage in a European data center:
Due to an overheating problem in our European data center many of our servers turned off to protect themselves. As this impacted all Wikipedia and other projects access from European users, we were forced to move all user traffic to our Florida cluster, for which we have a standard quick failover procedure in place, that changes our DNS entries.
This didn't really help because their failover mechanism failed. The worst part of this story, is that I'm trying to convince Kris, whom I gave a copy of my book to, that not everything is a freaking DNS problem: well, sometimes it bleeding well is. :-(