As low as 74¢ Per Month*

As low as 8.8¢ Per Minute

Always 0¢ Monthly Fee

As Long As 365 Days Re-Upping

* 74¢ per month after the first year at $7.40 per month for a discounted $100 card. The discounted $10/30 minute/90 day card works out to $3.07/month

Note, that the prices I have listed above reflect purchasing airtime cards at a discount from Calling Mart. See "http://www.callingmart.com/products/wireless/ProductDetail.aspx?ID=35". Search for a discount code to use. At the time of this writing, the code to use is "ca3p-1207" which takes 3% off of the listed 5% off price (discount codes will change, and there are often better discounts than the 3% which seems to always work).

T-Mobile To Go
The cheapest per month cost is on T-Mobile prepaid (http://www.t-mobile.com/shop/plans/default.aspx?plancategory=4), once you complete the more expensive first year (you have to buy $100 worth of airtime (1000 minutes) in order to achieve "Gold" status. Once you're "Gold," with T-Mobile you can use up the 1000 10¢ minutes by buying thirty 33¢ minutes a year ($10 refill card). As long as you top up with a $10 card every 12 months, you keep all your minutes for a cost of 83¢ per month. Though the $10 card normally is good for only 90 days, once you're "Gold" all future refill cards are good for a year.

Unfortunately T-Mobile's prepaid coverage leaves a lot to be desired. They now have limited off-network roaming for prepaid at no extra charge. T-Mobile seems to work well on the east coast, but poorly on the west coast. A lot of people love T-Mobile To Go, but a lot of people that have tried to use it in rural areas do not like it at all. If you expect to use your phone outside of major metropolitan areas then don't get T-Mobile To Go, get PagePlus instead.

In 2008, there was a rumor that T-Mobile had a huge price increase in their texting rates for prepaid to 20¢ send/20¢ receive from 10¢ send/5¢ receive (they raised their postpaid texting rate to 20¢ send/20¢ receive) , but this appears to be unfounded, as their web site still shows 10¢ send/5¢ receive.

Activation: T-Mobile will sell you an activation kit (SIM card) for your T-Mobile or unlocked GSM phone for $10, including 10 minutes of airtime. Buy T-Mobile SIM Card for T-Mobile or Unlocked GSM phone.

Network: T-Mobile

Monthly Fee: None.

Minimum cost: First year: $88.35 ($7.36/month), subsequent years: $10 (83¢/month).

Per-minute cost: 8.8-29¢.

Re-upping: $10 ($8.84 discounted price) every 365 days once you achieve "Gold" status. Of course you don’t lose any time you haven’t used during those 365 days as long as you re-up in time.

Handsets: You can use any unlocked or T-Mobile locked GSM phone (they'll sell you a phone fairly cheaply with the $100 card).

Pros: Very low monthly cost (after first year at $7.40/month it drops to 74¢/month), no monthly charge. Moderate per-minute cost with the highest value card (10¢).

Cons: Poorer coverage than PagePlus. You have to buy a SIM card unless you're getting a phone from T-Mobile, in which case it is included. High start-up cost if you want to get the lowest monthly cost. No AMPS.  No data services other than some very limited sites.

Where to Buy Service: Online from T-Mobile, or at some department stores such as Target (not online). Sometimes Target will have specials that include a phone and a $100 airtime card (instant Gold) for under $100.
 

Where to Buy Phones: T-Mobile often has promotions for a free or low cost phone with $100 of airtime.

Unlocked dual band GSM phones (North American bands) can be found at:  http://www.jr.com/JRSectionView.process?N=11914+217742&Ne=102065#GSM

Unlocked quad band GSM phones ("world phones) can be found at: http://www.jr.com/JRSectionView.process?N=11914+217744&Ne=102065#GSM

I have found the best deal to be the Motorola Quad Band V195  for $30, though I think they are now sold out of this model. Often T-Mobile has specials where they include a $25 airtime card. I had this phone unlocked so it can be used with foreign prepaid SIM cards.

Examples of how much time you’d get for different monthly costs (non-discounted prices):
$0.83: 2 minutes ($10/35 minutes every year (assuming Gold Status to achieve 365 day expiration)
$5: 46 minutes ($50/460 minutes every ten months (assuming Gold Status))
$10: 100 minutes ($100/1000 minute card every ten months)
$25: 250 minutes ($100/1000 minute card every four months)

If you use more than the absolute minimum, then it's probably best to buy the $100 card to get the 10¢ minutes, then buy the $10 card every year to keep the account active while you slowly deplete the 1000 minutes.

Voice Mail and Texting Uses T-Mobile's Systems

You can access the T-Mobile voice mail and texting systems. This means that the back-door voice mail number can be used to check your voice mail from a land line without using up any prepaid minutes which is a very nice feature. T-Mobile's voice mail back door is 805-637-7243. Not local, but you can use cheap or free landline long distance such as OneSuite or Google Voice to check your voice mail if you want to not use prepaid minutes. Send messages to T-Mobile phones using 10-digit number@tmomail.net.

Bottom line: A good deal for light users, once you get gold status. Still, the per minute rate even on the $100 card is pretty high, and they don't offer any data services on prepaid. Stick with PagePlus unless you really want to use a SIM card in your GSM handset.