Radio Shack on Thursday brought back its iPhone trade-in deals another time and added new check-in deals. Anyone can trade in an iPhone 3G or 3GS in good condition and get a $75 credit towards any iPhone in the store. An iPhone 4 drops to $125 or $225 on a contract; buying an 8GB iPhone 3GS not only gives the phone for free but adds a $25 gift card for the store.
