My friend has AT&T already (with a Blackjack) and is eligible for an upgrade, so he is considering iPhone 3G. The only problem is, he has an older 3G data plan that only costs him $19.99 a month that he would love to use with iPhone 3G. He's on a family plan with his wife who wants his blackjack, but doesn't care about a data plan. Tell me if this will work:

1. Use the upgrade on his wife's phone instead of his phone to get the iPhone 3G, subsequently extending his contract by 2 years.
2. Immediately cancel the iPhone data plan and say that he isn't planning on using the iPhone with service currently (but still accepts the contract extension).
3. Use a Turbo SIM to unlock the iPhone 3G, stick his Blackjack SIM into the iPhone 3G and give the Blackjack to his wife.

With iPhone 3G unlocked, his old 3G data plan should work just fine as long as it's unlocked, correct? I guess my biggest question is, can you get an iPhone 3G and then cancel the data plan, as long as you accept the fact that your contract has been extended for 2 years?

1.Yes, you can cancel the iphone data plan.
2.Using a turbo sim is not an unlock solution, so be careful what you say when using "unlock"
3. An x-sim solution will not be necessary for you. The iphone will accept the att sim card from the blackjack, since it's on the same network. Just pop it in and it should work. You may need to activate by jailbreaking the iphone if you ever want to restore the phone.

Ok so you're saying that he can cancel the iPhone data plan, stick in his Blackjack SIM without unlocking, and the iPhone will work with his $19.99 3G Blackjack data plan?

It should work with his 3G blackjack data plan. But he might get a message from AT&T that states that the data plan he is using is not compatible with an iPhone and he might incur extra charges. I have been using my non-iphone data plan with the iphone for 2-3 months now.. I haven't seen any extra charges on my bill yet.