Update, 10:22 am PST: I am now able to make calls, receive email, and use the network.
Update, 10:05 am PST: AT&T customer service confirmed that there is a major outage in Oregon and Washington and they are sending a technician out to fix it. They have no ETA on when it will be back up. This affects only the 2G network -- 3G is up and working.
Update, 9:50 am PST: Still no change. No incoming or outgoing calls, nor access to any network functions.
It's 9:00 am PST, just south of Portland, OR, and I am unable to dial out or receive calls on my first generation (firmware 2.0.1) iPhone. I confirmed the same experience with 3 of my co-workers. Data services are also down. I'll be looking for that credit on my next bill from AT&T.