The $10 / month cell phone plan (pure talk and Samsung a157v)

So my older kid just started middle school and I figure it was time to get him an actual working phone.  For the past year he's been using my old iPhone 4 (at&t model) like an ipod touch (no call capabilities).  I did some research and wanted the cheapest plan possible with voice and some texting.  At this point I don't think he needs any kind of data plan yet (that will come in probably a few years).

I ended up going with puretalkusa.com (at&t network).
$10 per month (all taxes and everything included.  You set a hard maximum and you will never be charged more than this amount).
130 min per month that rolls over forever (never expires)
300 sms messages per month.
no data.

At&t has an online form for unlock but for some reason it didn't work for me.  A phone call and 10 min later though I was unlocked.  Good site to check the lock status:
http://www.imei.info/
If you are using an at&t phone I believe unlocking is optional.  Either way I wanted the iPhone unlocked just to avoid any potential issues and to increase the resale value when I do eventually sell it.  I did go through the entire itunes backup/restore steps too.

Got the micro sim in 3 days and it was easy to setup.  Activating the sim on their website took maybe 5 min.  Micro sim cost was $5 but included 150 bonus minutes (which will of course roll over if we he doesn't use it all).  They also have a family share plane for $5 per additional line that adds another 60 min into the pool.  You can split the minutes between phones anyway you want.

There are cheaper plans out there that are voice only like on t mobile.  Virgin mobile has some cheap plans too but really if you want complete coverage you have to go with at&t or verizon.  Plus, I really wanted some texting included in the plan.  If you need data then straight talk is probably a better deal.

Highly recommended.  I think it's a great plan for a kid's first phone or somebody who doesn't need data (there is always freedompop (sprint network) if you want some free data).  I'm very satisfied with the service so far.

UPDATE:
Testing out h2o which is another at&t MVNO.
https://www.h2owirelessnow.com/pageControl.php?page=planMin

picked up a micro sim from amazon for < 10 cents:
http://www.amazon.com/gp/product/B005XB7RH0

Activated it, charged up $10 on it, install iphone app, install data apn profile to get data working (the app makes this easy to do).

So the big difference here is everything draws money from your $10 bucket (which expires in 90 days).
5 cents/min calls
5 cents/text
10 cents/MB

I really like how data is rolled in there. Nice feature for find my friend/find my iphone for a bit more security especially for kids. The disadvantage of having it all draw from one bucket is if your kid watches a few youtube videos on 3G it could empty the account and then he won't even be able to make or take a call. I guess it comes down to how much you trust your kid to control himself.

There is an h2o app to check balances and recharge.

I like how after every call it flashes how much you spent on that call, remaining balance, and expiration date. So there should be no surprises. I'll probably recharge $10 every time he hits $5 balance.

So for $10/month - 3 months you actually get everything in very tiny portions. Heh.

Puretalk also just added a 150MB data plan that also rolls over for an additional $10/month. Both sims are still active so I'll test H2O for a bit, check how fast his account drains, and then decide which to keep.

UPDATE 2:
The spammy red messages that keep popping up every time money was spent out of your account got to be too much.  It would sometimes even do it with a $0.00 deduction which is just stupid.  It's probably the biggest complaint on the amazon reviews and there doesn't seem to be a way to turn it off.  You will constantly get interrupted when doing things like just reading or using gps.  It really reduces the usability of the smart phone.  Since then I've gone back to puretalkusa and added the data plan.  H2O is cheap...too cheap for our use case.  Also, we got a lot of strange phone calls with H2O which never happened on pure talk.  Their web site is pretty horrible with confusing verbiage and very unclear/lack of usage/charge reports.  Everything about H2O screams sketchy.  But hey it does work and it is about the cheapest thing out there for very low usage situations if you can live with all the annoyances.  For me I'll pay a bit more and use puretalk which is very clear and straightforward.

UPDATE 3:
My son only used 55 MB of data over the last 30 days on puretalk so 150 MB/month should be plenty.  This is with very light use with mostly just some google hangout chats.
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UPDATE 8/25/2014:
If you need a dirt cheap basic GSM phone (for kids and such)  the Samsung a157v is pretty great for $13-$15 (goes on sale once in a while for < $8).  Fry's, walmart, and I think best buy all carry this locally.  It takes all of about 5 min to unlock: http://funtelligent.blogspot.com/2013/02/how-to-network-unlock-at-gophone.html
Then you can use whatever sim card you want (puretalkusa, h2o, etc). This phone uses a full size sim card so use adapters if you need to up size a micro or nano.  For just talk and text this is a really nice phone at a really good price.
If you want to add your own wallpapers just format a jpg or png file at 128X160 resolution.  For ringtones a 30 sec or less mp3 file will work.  Just plug in a micro usb cable, select transfer on the phone when prompted, and copy the media to the appropriate folders.  You have around 107MB of free space to play around with.

Both my kids have a Samsung a157v now.  I called up puretalk and converted my $10 flex plan to a $15 family plan. They shipped me a new sim card for free.  It was a regular/micro sim depending on which size you punched out..  I kept my 1300 minutes I had left in rollover.  For the extra $5 a month I pay I also get another 60 min that goes into my family pool which I can easily allocate between the 2 lines on the website.  So for $15 total a month I get 190 min for 2 lines with rollover.  That really is a fantastic deal.  They also track texting differently now.  Instead of separate buckets for minutes and texting, every 3 texts = 1 min used.  I guess I'm ok with that since my kids don't really text that much (at least yet).  It does simplify things.