If anyone is interested - it seems this may be a worldwide patent. I checked as I was considering the consequences if they went after card processors. Here's the European patent number: EP0501697. You can look it up here:
http://www.espacenet.com/access.htm
If this patent is not overturned and AT&T start pursuing it aggressively with card processors and their license fees are extortionate the situation could turn very nasty quite quickly - particularly if you rely on your liveliehood from your Internet business!
A lot of if's in the above but I think if you have a family to support and this is your only income you should consider that now is perhaps the time to diversify?