I'm in the process of terminating my contract with AT&T and switching back to Consumer Cellular.  I am a huge fan of the no-contract way they do business.  Whether you are a heavy phone user or a seldom user, they have an economical voice plan for you.  They are NOT designed for heavy data use, like streaming videos or gaming.  For affordable voice plans, I recommend you check them out: http://www.consumercellular.com/.

Their biggest limitation is in the choice of phones they offer.  For a long time, I was a holdout in the cell phone world.  I had a "free" cell phone from Consumer Cellular, but never carried it with me unless I was traveling, only using it rarely even then.  I was finally overcome with my desire for an iPhone 4S and bought one last year at Best Buy.  Of course, my only options were AT&T, Sprint, or Verizon.  I had been spoiled by Consumer Cellular's no long distance, no roaming, no contract service.  After consulting with friends, I decided on AT&T.  All along, I've been thinking about the day when I'd be able to go back to the good old days of Consumer Cellular and save myself a ton of money in the process.  I first had to overcome the multiple hurdles of activating my iPhone 4S on the Consumer Cellular network.  I read a lot about other users' experiences of switching to Consumer Cellular, and came across foreign words pertaining to cell phones like "jailbreak," "unlock," and "tethered."  I could see that I had some studying to do before taking the plunge.  A couple of blogs were particularly helpful: 1) http://www.hickendesign.com/site/2012/02/how-to-setup-your-iphone-or-ipad-on-consumer-cellular/ and its related site 2) http://www.hickendesign.com/site/2010/12/iphone-3gs-on-consumer-cellular-with-edge-data-working/.  Neither of these provided enough specific information about using the iPhone 4S with Consumer Cellular, because the writer, Mark, doesn't himself have that iPhone model.

So, I think I have enough information on how to proceed and I'll update you on my progress.  Feel free to share your experiences with Consumer Cellular and your iPhone 4S.  Together, we can help each other.