As I write this, I'm having to go through a us-based open proxy server. The reason? Most of NTL's services seem to have died in the last half hour or so. In fact, it appears that other ISPs have also had their services affected. So what the hell is going on?
I can't find this in the news yet so I don't know. Instead, I'd like you to think about this: if the net were to completely stop working tomorrow, how badly would you be affected? We, as computer users, should know best of all how important it is to have a backup plan in case things go wrong (well at least one backup plan, but more is better)
In short, never rely totally on the net being available, because just when you need it most, it'll probably die for a bit.