In this edition of Ask Maggie, CNET's Marguerite Reardon explains how wireless operators have manipulated the market to ensure you can't take your iPhone 4S to any other U.S. carrier you want.

Apple has begun selling an unlocked, contract-free version of the iPhone 4S here in the U.S. but those of you who have been waiting for this day to arrive are going to have to wait just a little bit ...

U.S. customers who were holding out for an unlocked iPhone 4S can now order their handset contract-free from Apple's online store. The unlocked iPhone 4S starts at $649 for the 16GB model, while ...