Princing plan from AT&T:

With a two-year contract, the price of an 8GB iPhone 3G will be $199; the 16GB model will be priced at $299.

Unlimited iPhone 3G data plans for consumers will be available for $30 a month, in addition to voice plans starting at $39.99 a month.

Unlimited 3G data plans for business users will be available for $45 a month, in addition to a voice plan.