Is there ANY way of unlocking a 4S?

I have switched to T-Mobile's value plan from AT&T. Is the only way of unlocking a 4S through AT&T, either online or in store? I have no service right now so I'm looking for any method that is the fastest...

On a side note I wish either AT&T or Verizon offered a "value plan" like T-Mobile does where you have a MUCH cheaper monthly rate under contract in exchange for no subsidized pricing...

Just called AT&T. Maybe I was lucky but the lady on the phone unlocked it for me. Just had to do a restore on iTunes.