The new iPhone 3G data plan/ monthly fee will go upto $10/month on AT&T. As per the press release of AT&T, the new iPhone 3G data plan will actually increase $10 US/month to $30 US/month.

Apart from this, a voice plan starting at $39.99 US/month is also needed. With this, the total monthly fee for using an iPhon 3G will increase $10 US/month or $240 US/month over a period of the new two year contract.

So, here are the price plans for a voice account, 450 minutes: $39.99, 900 minutes: $59.99, 1,350 minutes: $79.99 and Unlimited: $99.99. Family price plan options: 700 minutes: $69.99, 1,400 minutes: $89.99, 2,100 minutes: 109.99, 3,000 minutes: $149.99 and finally unlimited minutes: $199.99.