AT&T have updated their web site with 8 and 16 GB refurbished iPhone 3G units. The devices cost $149 for the 8GB model and $249 for the 16 GB model. Warranty is 90 days through AT&T and a year with Apple. Use this iphone warranty lookup tool to verify the duration of your warranty. A better idea might be SquareTrade who will warranty the iPhone 3G within the first 30 days even against accidental damage (though not loss – as in “I left it on the bus”) warrantysanta will take 35% off the cost of $120 or $144 cost of a two year warranty.
