The Web is an interesting place, when we start distributing systems over diverse physical locations fun things can happen. One person can have access to a resource, while another one is denied. Chicago says but it works for me while Columbus says, it's down for us. Today after a 4 or so hour outage of FedEx Web Services that's precisely what happened as the systems were coming on line.
Check out this screen shot
There are 2 browsers open both refreshed at the same time, one working, one not. The difference is Internet Explorer is seeing a network 100 miles away from the network that Firefox is seeing.
About 15 minutes later both were on-line. That's geek cool!